7

PRIVACY: WHAT HAVE YOU GOT TO HIDE?

“Nine scorpions in a bottle.”1

This classic description of the Court in the mid-twentieth century—borrowed by a recent biographer2—is singularly apt. As America spun from crisis to crisis in the years after World War II, its highest court stood fractured by bitter personal rivalries, ideological conflict, and political maneuvering. In 1953, when Chief Justice Fred Vinson died halfway through stalled deliberations in Brown v. Board of Education, leaving open a seat soon filled by Earl Warren, Justice Felix Frankfurter confided that Vinson’s passing was “the first solid piece of evidence I’ve ever had that there really is a God.”3 Thrown together by the politics of appointments, the midcentury justices seethed and struggled inside the Marble Palace. Scorpions, indeed.

Ours is an age of comparative harmony. Justice Kagan won immediate goodwill on the Court by acquiring a frozen yogurt machine, and she now jokes that she will forever be remembered as “the frozen yogurt justice.”4 When Justice Alito first arrived, Justice Breyer arranged a celebratory dinner and invited a special guest from Alito’s hometown baseball team.5 “He opened the door,” Alito recalls, “and the Phillie Phanatic came in and gave me a big hug. And it was great.” Justice Ginsburg, soft-spoken and steely, is famously close with brash and wisecracking Justice Scalia—a friendship grounded in their love of opera and shared sense of humor. As Ginsburg fondly admits, Scalia “is one of the few people in the world who can make me laugh.”6

Still, the Roberts Court isn’t all flowers and hugs. The justices may be friendly, but they are also fierce and competitive participants in a struggle to define the Constitution. Each was carefully chosen by a president who sought a gladiator to champion particular ideals, whether through sheer force of intellect or the subtler arts of persuasion. Collegiality and compromise enjoy an important role on the Court, but it is ultimately a limited one. A shifting matrix of alliances, betrayals, and bitter defeats quickly teaches new arrivals that no vote can ever be taken for granted. Although ours is not an age of scorpions, the Court is still rife with intrigue and power struggles.

That drama unfolds awkwardly in a semitransparent institution. The image of scorpions in a bottle evokes both painful claustrophobia and an intrusive public eye, and in this way the metaphor applies to every era of the Court. In our Internet age more than ever, though, the justices carefully calibrate how much information they willingly reveal to outsiders. Some of these safeguards reflect principles of fairness: it wouldn’t do to permit anyone to profit politically or financially by obtaining advance notice of how cases will be decided. Other policies protect the integrity of the Court’s deliberative process: if the first round of tentative votes were announced, or if all deliberations were thrown open to the public, the justices might feel less willing to speak freely or change their minds. Still other privacy rules are meant to protect the Court’s reputation and the justices’ personal lives.

Nowhere are these concerns more pronounced than in the debate about whether to allow cameras in the courtroom. Despite vehement criticism by journalists and legislators, most justices firmly oppose televising oral arguments.7 Aware that recordings could be manipulated or distorted, some of them see little benefit to cameras—and great potential for mischief. Justice Sotomayor has warned that “very few [viewers] understand what the process is, which is to play devil’s advocate,”8 and Scalia has bluntly insisted that “it will misinform the public … to have our proceedings televised.”9 Ever protective of judicial integrity, Justice Kennedy has explained why he views cameras as dangerous: “Our dynamic works. The discussions that the justices have with the attorneys during oral arguments is a splendid dynamic. If you introduce cameras, it is human nature for me to suspect that one of my colleagues is saying something for a soundbite. Please don’t introduce that insidious dynamic into what is now a collegial court.”10 Kennedy added that the Court’s policy sends a considered message about its role: “We teach, by having no cameras, that we are different. We are judged by what we write. We are judged over a much longer term. We’re not judged by what we say.”

Cameras also cause the justices to worry about privacy in their personal lives. Justice Thomas, for example, has cautioned that “regular appearances on TV would mean significant changes in the way my colleagues conduct their lives.”11 Referring to his bruising confirmation fight, he elaborated, “My anonymity is already gone, [and] it’s already affected the way I conduct my own life. But for some of my colleagues, they’ve not yet lost that anonymity.”

The Court’s formal policies make up only part of the justices’ choices about how to go about their lives outside their sanctum. During the summer recess, Thomas likes to tour the nation with his family in a forty-foot customized RV, camping out at Walmarts and stopping to watch NASCAR races. Scalia mixes old-fashioned hunting trips with an active and battle-ready presence on the national lecture circuit. Breyer and Scalia have both published popular works of legal theory, while Sotomayor and Thomas have offered intensely personal accounts of their remarkable life stories.12 Ginsburg has recently taken a star turn, describing her experience as a woman on the Court and speaking out publicly against “one of the most activist courts in history.”13 Alito, in contrast, tends to favor intimate events sponsored by law schools and conservative groups.14 As every member of the Court knows well, there are many kinds of privacy, ranging from anonymity at the supermarket to shielding one’s childhood traumas from public awareness. The justices vary widely in striking the public-private balance that works for them as individuals.

Sometimes, however, a justice is forced roughly into open view. Confirmation hearings involve merciless investigation of every aspect of a nominee’s life, from temperament to sexual orientation. Near the end of many presidencies, politically motivated calls for one justice or another to resign prompt invasive questioning into justices’ health and future plans. Unpopular judicial decisions can trigger public denunciations, ranging from mild editorials to burnings in effigy. In 2006, after Justice David Souter joined an opinion upholding a government confiscation of private property, radical conservatives forced a vote in Weare, New Hampshire, on whether to seize Souter’s beloved farmhouse.15 Their efforts to forcibly convert his home into what they dubbed the “Lost Liberty Hotel” failed, but they brought the prying eye of the media into Souter’s private life. Baseless calls for Thomas and Kagan to recuse themselves in the Health Care Case triggered inquiries into Kagan’s e-mail correspondence at the Department of Justice and political activities by Thomas’s wife.16

If privacy at the Court can be elusive, the same is increasingly true for many Americans. We live in the era of the PATRIOT Act; sweeping electronic surveillance by the National Security Agency; the collection of massive amounts of consumer information by such companies as Google, Amazon, and Facebook; GPS tracking, data mining, spy satellites, thermal sensors, and drones; and smartphones, navigators, and household appliances that chart our every movement. Privacy is not what it used to be. At times, it seems like a casualty of technology.

The Roberts Court has only just begun to mark the outlines of what the Constitution will (or will not) say about twenty-first-century privacy. In cases involving DNA databases, drug-sniffing dogs, GPS tracking of cars, and text messages, it has adopted a cautious approach to our brave new world. Aware that privacy’s older paradigms need to be updated or replaced, the Court has rendered narrow rulings on broad issues, buying time to reflect before it directly confronts the big questions.

True to form, Scalia has sought a rebirth of originalist approaches to privacy law; at nearly every turn, though, he has been opposed by Alito, who has focused on evolving societal expectations and the role the other branches of government should play in policing the police. Sotomayor, willing to reconsider foundational precedents and more open to an active judicial role, has emerged as an eloquent champion of privacy’s importance. Kagan and Kennedy, in contrast, have preferred to acknowledge the demands of modernity while avoiding firm commitments to particular reforms. All of the justices, though, have made clear their intense interest in these still-evolving debates. As Kagan observed in 2013, privacy issues are “a growth industry for the court.”17

At the Roberts Court, the Constitution’s uncertain role in protecting our privacy is up for grabs. And as the justices struggle inside their bottle to craft law adequate to the needs of this era, our national values hang in the balance.

*   *   *

The Fourth Amendment protects “the right of the people to be secure in their persons, houses, papers, and effects” against “unreasonable searches and seizures.” Atop this slender reed, the Court has built an enormously complex system of rules designed to protect certain kinds of privacy from unjustified government invasion.18 Many of these rules are of recent vintage: only in the twentieth century did the Court embrace a broad vision of the Fourth Amendment. This ongoing project remains bedeviled by hard questions about what privacy means, how it stacks up against competing values, and what role courts should play in protecting it.

Privacy takes many forms.19 Among other things, it consists of secrecy and solitude, but it also transcends them. It covers control over our bodies, reputations, and personal information. It ebbs and flows in different settings, waxing in our homes and waning in public. It varies wildly from culture to culture, and across history and social groups within cultures. Its meaning can change with evolving social expectations, even as the kinds of privacy we experience shape the views we come to hold. Despite its shifting shape, five aspects of the right to privacy provide crucial context to the Roberts Court’s central Fourth Amendment rulings.

First and foremost, the right to privacy is a social right. It isn’t only about secrecy, which involves the complete refusal to share something with others. Privacy also encompasses decisions about what to share, whom to share it with, and when and how to share it. This sort of selective control over personal information is profoundly important: just imagine if your coworkers knew everything about you that your parents know, or if your credit card company shared your files with a first date. Even in an age of indiscriminate sharing on social media sites such as Facebook, each of us tries to maintain informational boundaries that only certain other people can cross. Trusting someone with our innermost thoughts, feelings, and experiences is the surest foundation for establishing and defining relationships—ranging from our most casual acquaintances to our deepest love. The right to limit the group of people entrusted with our personal information is therefore directly related to the right to flourish in society.

Second, the right to privacy includes the right to establish our own identity, to emphasize the accomplishments and attributes we care most about. Are you a gay NBA star or an NBA star who happens to be gay? Or someone who doesn’t tell anyone about his sexuality? The basketball player Jason Collins explained his own dilemma in an open letter published in Sports Illustrated: “I’m a 34-year-old NBA center. I’m black. And I’m gay.… I wish I wasn’t the kid in the classroom raising his hand and saying, ‘I’m different.’ If I had my way, someone else would have already done this. Nobody has, which is why I’m raising my hand.”20 What we tell others—and how and when and why we do so—is intimately related to how we think about ourselves. The creation of our own identities is impossible without a measure of privacy. Often, we make self-discoveries only at the moment we vocalize them. The right to shape our identity is thus nothing less than the right to control the course of our lives.

The right to privacy encompasses, third, the right to leave our past behind and experiment with different futures. We have all made mistakes, from a hastily written e-mail to youthful indiscretions to substance abuse. As Alexander Solzhenitsyn once wrote, “Everyone is guilty of something or has something to conceal. All one has to do is look hard enough to find what it is.”21 Privacy lets us escape the suffocating weight of these missteps, to reinvent ourselves and be judged as the people we are, not the individuals we once were. Alexander Pope thought that “to err is human; to forgive, divine,”22 but respect for privacy is itself a form of societal forgiveness that shouldn’t depend on divine intervention. It is also a principle on which any open society depends. When our every move is recorded and cataloged, innovation and experimentation suffer; behavior turns toward the mainstream and conformity seems the safest path. The knowledge that our past will not haunt us forever is liberating. It helps unleash the whimsical, radical, and generative energies essential to democratic culture and economic innovation.

Fourth, the right to privacy is the guardian of many other rights. The religious need it to pursue their faith. Political activists need it to hone their arguments and plan their protests. Academics need privacy to bounce wild ideas off students, and businesses need it to test new products. We all need privacy to figure out what we care about, what upsets us, and what turns us on. The Court recognized this deep connection in 1969 when it held that the possession of obscenity in the privacy of one’s home is protected as a facet of broader personal freedoms.23 “Our whole constitutional heritage,” Justice Thurgood Marshall wrote, “rebels at the thought of giving government the power to control men’s minds.” Life under constant surveillance is incompatible with full enjoyment of our liberties.

Finally, the right to privacy is a requirement of democracy. When none of us can be certain what the state knows about us or how it might use that information, the relationship between the governed and the government is fundamentally altered. The state’s unlimited access to whatever information it wishes to obtain about each citizen can create a profound power imbalance and feeling of vulnerability. As Justice Robert Jackson once wrote of searches and seizures, “Among deprivations of rights, none is so effective in cowing a population, crushing the spirit of the individual and putting terror in every heart.”24 This is especially true when the state develops the ability to combine many small pieces of data into a full picture of our lives. Even if we trust the state not to abuse the information and search only for true threats, the risk that our vast intelligence bureaucracy will make an egregious error is unavoidable. Entirely innocent personal information can be abused, leaked, distorted, and put to mischievous use in unpredictable ways. Without protection of privacy, democratic life could suffer a dangerous chill.

As the Roberts Court knows, privacy is vital but delicate. Every major technological breakthrough of the twentieth century prompted warnings of privacy’s demise. Offering a measure of perspective, Deborah Nelson has remarked, “Privacy, it seems, is not merely dead. It is dying over and over again.”25 Yet it is no exaggeration to say that privacy is now threatened as never before. We are studied by government, political campaigns, universities, and retailers. We share detailed information with sites like Twitter, Facebook, Tumblr, Google, and OkCupid. Our smartphones and Kindles create records of our habits. Drones, closed-circuit cameras, and thermal sensors reveal what was once hidden. Analysts create ever more powerful tools for discovering useful patterns in seemingly isolated fragments of information. The world imagined by George Orwell in 1984 seems more and more possible: “Always the eyes watching you.… Asleep or awake, working or eating, indoors or out of doors, in the bath or in bed—no escape. Nothing was your own except the few cubic centimetres inside your skull.”26

New technologies also mean that our personal information is of interest to a large number of actors who have many ways of obtaining it. As the New York Times reported in 2012, “Almost every major retailer, from grocery chains to investment banks to the U.S. Postal Service, has a ‘predictive analytics’ department devoted to understanding not just consumers’ shopping habits but also their personal habits, so as to more efficiently market to them.”27 The national retailer Target, for example, has reportedly assigned many of its shoppers an individual code, which it uses to track age, marital status, hometown, estimated salary, favorite websites, and job history. Through information traders, Target also has access to data about ethnicity, magazine preferences, favorite coffee brands, political leanings, and charitable giving—all of which allows the company to identify and appeal to key demographics, such as new parents, by sending timely special offers. Each of us now receives a level of personal surveillance that, in decades past, was reserved for national figures like the justices.

But the right to privacy cannot be considered in a vacuum, because it is in constant competition with other values.28 A free flow of data supports entrepreneurship, creativity, and innovation. Limiting others’ ability to share our information may infringe on their free speech rights and their control over intellectual property. Expanded surveillance has enhanced local and national security, as terrible crimes are often planned behind closed doors or a veil of anonymity. Facebook’s privacy settings offer limited protection, but it is now easier than ever before to develop, maintain, and rekindle relationships all over the world. Access to information about us allows retailers and politicians to target their messages more effectively, scholars to better understand society, and government to more capably provide social services. By voluntarily sharing personal data with companies from eBay to Apple, we obtain personalization and convenience. While informational privacy doesn’t always come at the cost of security, efficiency, or convenience, that trade-off has become a fixture of American life.

In that dynamic, individuals are not always, or even often, the key players. Though it’s up to us whether to “like” posts on Facebook or confess secrets on Twitter, we have no choice but to leave a revealing trail of information—about where we go, whom we see, what we say, and how we spend our money. Each of us is regularly matched to medical, cell phone, bank, insurance, Social Security, and tax records. Benjamin Franklin once remarked that “three can keep a secret, if two of them are dead,”29 but now even a single person must struggle to retain privacy.

Indeed, in the modern world, privacy rarely exists by default.30 Instead, privacy is the product of myriad choices made by individuals, businesses, and governments about how to organize access to information. If you give the clerk at Old Navy your phone number, who else gets it? Will Google resist government requests for your e-mail records? Can the police use the GPS in your iPhone to track your movements? Decisions about these kinds of issues are governed by an overlapping network of rules that include corporate privacy policies, state and federal laws and regulations, and “new governance” schemes in which private businesses partner with governments to share information. Especially in the corporate and national security fields, many of these privacy rules are themselves secret—though, as the National Security Agency learned in 2013, few programs remain hidden forever.31 Even when secret, the rules governing privacy rarely aim to provide either total confidentiality or unlimited access. Rather, they specify what requirements must be met to invade certain aspects of our privacy, how information can be used, and whether to permit transparency and accountability. To see this balancing act at work, just check the privacy policy on your next online purchase—if you can manage to read the fine print and fathom its meaning.

Courts play a limited, but important, role in protecting our right to privacy from the government. For instance, when Congress, the states, or other regulators haven’t imposed specific limits, the police are restricted mainly by the Fourth Amendment. Since there are only a handful of statutes and regulations that protect our privacy, and since many of them are badly out of date, the first issue about questionable police conduct is often whether it constituted a “search” or “seizure.”32 If so, the Fourth Amendment is triggered and the officers’ conduct must be “reasonable.”

Reasonableness, often described as the touchstone of the Fourth Amendment, is determined by an intricate series of context-sensitive rules. These doctrines govern what level of police suspicion justifies a particular type of search, when a judicially approved warrant is required, when a type of search is deemed unreasonable regardless of the specific circumstances, how searches must be executed, and a lot more. Failure to comply with these rules is risky: any evidence discovered during a search later determined to be unreasonable may be subject to suppression in court, and in some cases the officers may be vulnerable to a civil rights suit. The Fourth Amendment thus keeps the government and its agents accountable and imposes boundaries on searches that might otherwise allow the police to indiscriminately rummage through people’s lives.

But the Fourth Amendment shields only certain kinds of privacy from invasion by particular actors. It doesn’t affect the conduct of private businesses, gossipy friends, or even most government practices. As a result, for all their power, judges will never be privacy’s savior. Still, the Court’s rulings are profoundly important. They express our values and fears, shape social expectations, and sometimes impose robust limits on the government’s most far-reaching surveillance activities. At a time when the government’s partial secrecy about intelligence programs prevents voters from holding their leaders fully accountable, the Court’s pronouncements on the Fourth Amendment are understood as binding even in the darkest caverns of the National Security Agency. Accordingly, the lines the Court draws matter to every one of us—especially since the Roberts Court is in the middle of a foundation-shaking reappraisal of those principles.

*   *   *

Charles Katz liked to gamble. In the 1960s, he made a business of it, with clients in Los Angeles, Miami, and Boston. When he placed bets for them over the phone, though, he violated a federal statute criminalizing interstate wagering by wire. To evade detection, he made most of his calls from a public phone booth. This trick did not succeed. The FBI eventually caught on and attached an electronic listening and recording device to the outside of a booth Katz favored. The federal agents didn’t have a warrant, but precedent at the time strongly suggested that they didn’t need one. Relying on taped conversations, federal prosecutors successfully convicted Katz. On appeal to the Court, Katz argued that the FBI had violated his Fourth Amendment rights in eavesdropping on his private conversations.

From the outset, it was clear to at least some of the justices that Katz v. United States afforded a vehicle to reverse one of the Court’s greatest mistakes: Olmstead v. United States.33 Decided in 1928, Olmstead held that wiretapping a phone is not a “search” within the meaning of the Fourth Amendment. It reasoned that the Constitution’s protections of privacy are limited solely to invasions of personal property. Searches that trigger the Fourth Amendment, therefore, must be of “material things—the person, the house, his papers, or his effects.” A wiretap, the Court argued in Olmstead, involves “no entry of the houses or offices of the defendants.” Instead, evidence is “secured by the use of the sense of hearing and that only.” Under this logic, which pegged privacy protections to property rights, police were free to tap every phone line in America without obtaining a warrant and without even a reasonable basis for suspecting wrongdoing.

Olmstead was wrong the day it was decided, a fact memorialized in one of the Court’s greatest dissents. Justice Louis Brandeis warned against a narrow focus on property, explaining that “clauses guaranteeing to the individual protection against specific abuses of power, must have a similar capacity of adaptation to a changing world.” Refusing to treat wiretaps as a search made no sense where “discovery and invention have made it possible for the government, by means far more effective than stretching upon the rack, to obtain disclosure in court of what is whispered in the closet.”

Writing with the force of prophesy, Brandeis declared that the right to privacy must be conceived in grander terms: “The makers of our Constitution undertook to secure conditions favorable to the pursuit of happiness. They recognized the significance of man’s spiritual nature, of his feelings and of his intellect. They knew that only a part of the pain, pleasure and satisfactions of life are to be found in material things. They sought to protect Americans in their beliefs, their thoughts, their emotions and their sensations. They conferred, as against the government, the right to be let alone—the most comprehensive of rights and the right most valued by civilized men. To protect that right, every unjustifiable intrusion by the government upon the privacy of the individual, whatever the means employed, must be deemed a violation of the Fourth Amendment.”

Brandeis also dismissed the wiretappers’ apparently noble goals: “Experience should teach us to be most on our guard to protect liberty when the government’s purposes are beneficent.… The greatest dangers to liberty lurk in insidious encroachment by men of zeal, well-meaning but without understanding.”

When Katz reached the Court in 1967, principles announced in Olmstead framed the debate. Katz urged the justices to treat the phone booth as a “constitutionally protected place,” subject to all the property-based protections of a house. Placement of the recording device, on that theory, was something akin to a trespass by the government—and thus an action that required a warrant under Olmstead.

The Court initially split four to four and seemed resigned to affirming the lower court ruling without any opinion. But after weeks of debate in chambers, a coalition of seven justices voted to overrule Olmstead and broadly extend Fourth Amendment coverage. Writing for the majority, Justice Potter Stewart laid down a new rule: “The Fourth Amendment protects people, not places. What a person knowingly exposes to the public, even in his own home or office, is not a subject of Fourth Amendment protection. But what he seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected.”

Stewart rejected Olmstead’s insistence that the Constitution guards privacy only in certain places, or where we have property rights. Instead, he invoked our expectations of privacy: “The Government stresses the fact that the telephone booth from which the petitioner made his calls was constructed partly of glass.… But what he sought to exclude when he entered the booth was not the intruding eye—it was the uninvited ear.… One who occupies [a phone booth], shuts the door behind him, and pays the toll that permits him to place a call is surely entitled to assume that the words he utters into the mouthpiece will not be broadcast to the world.” In an influential concurrence, Justice John Marshall Harlan framed a two-part test: the Fourth Amendment is triggered when a person has an actual expectation of privacy and society is prepared to view that expectation of privacy as reasonable.

Implicitly linking the First and Fourth Amendments, Stewart added, “To read the Constitution more narrowly is to ignore the vital role that the public telephone has come to play in private communication.” Because universal access to unmonitored communication in the 1960s turned mainly on use of public phones, he reasoned, the Constitution must protect privacy in places like phone booths. Katz thus recognized that an interplay of changing social norms, technologies, and police needs would shape privacy law.34

Katz attracted widespread support because it outlined a fragile middle ground: when individuals expect privacy and society is prepared to view that expectation as reasonable, government intrusions constitute a “search” for Fourth Amendment purposes. Liberals were satisfied that government would not be granted unlimited authority to spy on all its citizens. Conservatives felt confident that the police could continue to investigate crimes effectively. And both groups understood that Katz provided a framework for the security-versus-privacy debate without prematurely resolving many of its thorniest issues.

In 1979, faced with one of the most important post-Katz questions, the Court dealt a significant blow to the Fourth Amendment’s privacy protections. In Smith v. Maryland, it held that the installation of a “pen register,” which records all numbers dialed from a specific telephone, does not constitute a “search.”35 The Court emphasized that the defendant had every reason to believe that the telephone company knew what numbers he dialed—and thus had no “reasonable expectation of privacy” with respect to that information.

Smith has become central to what is now called the “third-party doctrine,” which holds that we typically lose any reasonable expectation of privacy regarding information that we have provided to someone else. Given that our bank, Internet, credit card, cell phone, and GPS records are all available to third parties—many of them private businesses—this doctrine, applied broadly, could devastate modern privacy. And it rests on the counterintuitive theory that, by allowing particular third parties to see our information, we lose any expectation of privacy vis-à-vis the government—even though privacy often involves selective disclosure, not pure secrecy. We might want to let American Express or Yahoo know things for particular purposes, but we don’t necessarily want that information to get into the hands of Uncle Sam, especially because the government can then freely combine information from many other private actors.36

Dissenting in Smith, Stewart lambasted the majority for its broad reading of third-party doctrine. He also disagreed with the Court’s assertion that the numbers dialed from a private phone, unlike the conversation itself, are without “content.” As he explained, “Most private telephone subscribers may have their own numbers listed in a publicly distributed directory, but I doubt there are any who would be happy to have broadcast to the world a list of the local or long distance numbers they have called. This is not because such a list might in some sense be incriminating, but because it easily could reveal the identities of the persons and the places called, and thus reveal the most intimate details of a person’s life.” This argument has particular modern currency because of debates over the National Security Agency’s reliance on Smith to justify surveillance of “metadata,” which is incisively defined by Slate’s Dahlia Lithwick and Georgetown’s Steve Vladeck as “the details of when, where, and how we used the Internet—not what we actually read or wrote.”37 However meaningless a single bit of information may seem, metadata can be assembled into an illuminating picture of our lives.38

Katz and Smith thrust the Court into debates about the uncertain architecture of Fourth Amendment doctrine: what it would protect and how it would respond to changing technology. Since then, a succession of justices has struggled to hammer out rules that apply Katz and Smith to rapidly evolving circumstances. Over the past few years, the Roberts Court has stepped cautiously into that breach.

*   *   *

At argument, it isn’t usually an auspicious sign when a justice describes something bad and asks the government, “Are you saying you can do that to me?” Deputy Solicitor General Michael Dreeben may therefore have felt a pang of foreboding while arguing United States v. Jones, a 2012 case about the government’s power to attach GPS trackers to cars.39 Striking to the heart of the matter, Chief Justice Roberts asked, “You think there would also not be a search if you put a GPS device on all of our cars, monitored our movements for a month? You think you’re entitled to do that under your theory?” Taken aback, Dreeben asked, “The justices of this Court?” “Yes,” Roberts bluntly replied, as nervous laughter filled the courtroom. Driving his point home, the Chief said, “So your answer is yes, you could tomorrow decide that you put a GPS on every one of our cars, follow us for a month; no problem under the Constitution?” Dreeben couldn’t deny it.

The government lost in Jones by a vote of nine to zero, though the Court split over why the Constitution required that result. The government lost again, one year later, in Florida v. Jardines, another major privacy case, this one about when the use of a drug-sniffing dog counts as a search. In Jardines, though, the vote was five to four.40 Both cases fractured the Court in unusual ways, revealing deep divisions about the Fourth Amendment’s future. In both cases, Scalia wrote the majority and Alito wrote an opinion disagreeing with Scalia’s logic. Also in both, one of Obama’s appointees wrote separately: in Jones, Sotomayor proposed far-reaching changes; in Jardines, Kagan wrote to limit Scalia’s originalist opinion and propose common ground between him and Alito.

Jones was set in motion in 2005, when Antoine Jones, the owner of a nightclub in Washington, D.C., came under suspicion of drug trafficking. Although they lacked a valid warrant, federal agents installed a GPS tracker on the undercarriage of his Jeep. They then spent twenty-eight days tracking the Jeep’s every move, including Jones’s visit to a cocaine stash house later found to contain ninety-seven kilograms of cocaine, $850,000 in cash, and one kilogram of cocaine base. Relying in part on the GPS data, a jury convicted Jones and a judge sentenced him to life in prison without the possibility of parole.

Jardines followed from an unverified tip to the Miami-Dade Police Department that Joelis Jardines was growing marijuana in his house. Police surveilled the house but could not see anything, so they sent a trained drug-sniffing dog to investigate. As Kagan recounted in her concurrence, “Officers came to Joelis Jardines’ door with a super-sensitive instrument, which they deployed to detect things inside that they could not perceive unassisted. The equipment they used was animal, not mineral.” That dog, she added, “was not your neighbor’s pet, come to your porch on a leisurely stroll … [he was] to the poodle down the street as high-powered binoculars are to a piece of plain glass.” Franky, the police dog, immediately picked up the scent of marijuana, ran to sniff the home’s front door, and then sat down to signal that he smelled drugs. Based on this identification, the police obtained a search warrant that led to the discovery of live marijuana plants. Jardines was charged with drug trafficking. He filed a motion to suppress the evidence, arguing that it had been illegally obtained.

Scalia saw both cases in terms of the link between privacy and property, writing opinions that sounded a lot like Olmstead, although he claimed conformity with Katz. In Jones, joined by Roberts, Kennedy, Thomas, and Sotomayor, Scalia deemed the police conduct a search because the government had placed a GPS tracker on the Jeep. As he explained, “The Government physically occupied private property for the purpose of obtaining information,” and “we have no doubt that such a physical intrusion would have been considered a ‘search’ within the meaning of the Fourth Amendment when it was adopted.” In Jardines, joined by Thomas, Ginsburg, Sotomayor, and Kagan, Scalia reasoned that the police physically entered a “constitutionally protected area” when they approached the front porch of the house. He added that the police had gathered information by engaging in “conduct not explicitly or implicitly permitted by the homeowner.” Whereas few would doubt that police are free to walk up to a front porch, “an invitation to engage in canine forensic investigation assuredly does not inhere in the very act of hanging a knocker.”

To Scalia, the attachment of a GPS tracker in Jones was a search because it involved a trespass; the conduct in Jardines was a search because it exceeded the implied license to enter property for limited purposes. In neither case did Scalia ask the typical post-Katz question: did the government’s conduct violate reasonable expectations of privacy and thereby constitute a search subject to Fourth Amendment limits? Instead, he looked mainly to centuries-old rules governing property rights.

This was hardly surprising, because Scalia is, first and foremost, a lover of clear rules, tradition, and original understanding. The Katz test, which offers a vague and evolving standard for defining Fourth Amendment rights, offends his legal sensibilities. As he noted at argument in Jones, “I think that [Katz] was wrong. I don’t think that was the original meaning of the Fourth Amendment.” Conceding that “it’s been around for so long, we are not going to overrule that,” Scalia has nonetheless made clear his determination to ensure, at the very least, that Katz doesn’t end up depriving us of privacy rights promised by the framers. It is not difficult to imagine how that might happen: given the intrusive new technologies now available to both business and government, our reasonable expectations of privacy could drop below a baseline that would have been taken for granted in the 1790s.

As usual, Scalia didn’t trust judges to keep a steady eye on their compass while searching for clear lines in the shifting sands of modernity. Without a firm rule—such as the one he offers in Jones—how are we to know when around-the-clock GPS tracking has gone too far? And what if, by frequently tracking people this way, the police bring about the expectation that we are never really alone? In Scalia’s view, the Constitution imposes limits on the government apart from what the public expects or even desires: “We must assure preservation of that degree of privacy against government that existed when the Fourth Amendment was adopted.” Katz may add to our privacy rights, Scalia declared, but it may not subtract. An originalism-based approach keyed to physical intrusions on protected areas always provides a constitutional minimum.41

In a separate concurrence joined by Ginsburg, Breyer, and Kagan, Alito echoed Scalia’s doubts about Katz: “The Katz test rests on the assumption that this hypothetical reasonable person has a well-developed and stable set of privacy expectations. But technology can change those expectations.” Citing articles entitled “The End of Privacy” and “Everything About You Is Being Tracked—Get Over It,” Alito conceded that Katz can cause privacy rights to vary either up or down, as technology evolves.

Alito’s agreement with Scalia, however, extended no further. Alito especially objected to Scalia’s reliance on history to save privacy’s future. In general, he views Scalia’s originalism as quaint and blind to modern developments. (Scalia, in turn, views Alito’s preference for a cautious balancing of constitutional values and technological trends to be dangerously uncertain and insensitive to the preservation of our rights.) Thus, in Jones, Alito’s Burkean instincts rebelled at Scalia’s suggestion that there is nothing new under the sun. As Alito put it, whereas Scalia insisted on deciding Jones “based on 18th-century tort law,” he preferred to “apply the Fourth Amendment’s prohibition of unreasonable searches and seizures to a 21st-century surveillance technique.” Alito took obvious delight in mocking Scalia’s equation of GPS tracking with obsolete police practices: “Is it possible to imagine a case in which a constable secreted himself somewhere in a coach and remained there for a period of time in order to monitor the movements of the coach’s owner?” Alito wryly added, “The Court suggests that something like this might have occurred in 1791, but this would have required either a gigantic coach, a very tiny constable, or both—not to mention a constable with incredible fortitude and patience.”

Alito also warned that Scalia’s property-based approach had little to say about instances of GPS tracking that involve remote activation of built-in GPS systems. This is particularly problematic in light of the third-party doctrine: rather than conducting any kind of physical search, the police could simply call up our phone or car companies to obtain our tracking data from them. Scalia’s rule in Jones may set a useful floor on some police conduct, but in most cases it probably won’t accomplish much.

Rejecting Scalia’s property-based approach, Alito argued that the Court should have decided Jones on reasonable expectation of privacy grounds. As he freely admitted, this was no easy task. That is why, he explained, it would have been better for Congress to create statutory limits on surveillance: “A legislative body is well situated to gauge changing public attitudes, to draw detailed lines, and to balance privacy and public safety in a comprehensive way.” Indeed, given “dramatic technological change,” Alito suggested that “the best solution to privacy concerns may be legislative.” But in 2012, Congress had not passed such privacy legislation, and Alito had to address the constitutional issue.

In his view, the police had crossed a line: while we don’t usually have an expectation of privacy in our public movements, “the use of longer term GPS monitoring in investigations of most offenses impinges on expectations of privacy.” For minor offenses like drug trafficking, he reasoned, “society’s expectation has been that law enforcement agents and others would not—and indeed, in the main, simply could not—secretly monitor and catalogue every single movement of an individual’s car for a very long period.” With this statement, Alito embraced a version of what has become known as “mosaic theory”—the notion that, even if individual acts of surveillance, considered independently, do not constitute a search, a cumulative pattern of such acts might trigger the Fourth Amendment.42 As natural as this may sound, it is a marked departure from prior cases, which have focused on discrete acts of surveillance rather than the whole symphony of government conduct.43

Alito suggested in Jones that GPS tracking may call for a probing reevaluation of Fourth Amendment rules about the government’s freedom to follow our public movements. He is not alone. As Chief Judge Alex Kozinski of the Ninth Circuit Court of Appeals observed in 2010, “A small law enforcement team can deploy a dozen, a hundred, a thousand such devices and keep track of their various movements by computer, with far less effort than was previously needed to follow a single vehicle.… There’s no hiding from the all-seeing network of GPS satellites that hover overhead, which never sleep, never blink, never get confused and never lose attention.”44 These tools trouble some judges not only because they are readily available, but also because they are uniquely revealing. The New York State Court of Appeals thus warned in 2009, “Disclosed in the data retrieved … [will be trips] to the psychiatrist, the plastic surgeon, the abortion clinic, the AIDS treatment center, the strip club, the criminal defense attorney, the by-the-hour motel, the union meeting, the mosque, synagogue or church, the gay bar and on and on.”45 This technology thus yields a full picture of our lives. As Breyer remarked at oral argument in Jones, if “there is nothing to prevent the police or the government from monitoring 24 hours a day the public movement of every citizen of the United States … you suddenly produce what sounds like 1984.” Kozinski put it even more bluntly—and personally: “There is something creepy and un-American about such clandestine and underhanded behavior. To those of us who have lived under a totalitarian regime, there is an eerie feeling of déjà vu.”

Mosaic theory approaches to the Fourth Amendment, however, are hard to put into practice.46 When does the sum total of a surveillance program become a search? Does the amount of surveillance constituting a search vary with the seriousness of the crime being investigated? When police conduct a search under the framework of this theory, do they need a warrant, or will some lesser showing of suspicion suffice? More broadly, how can the police be expected to protect the public adequately when they are guided by such vague rules?

In Jones, Alito dodged the thorny issues of formulating a clear judicial approach to the burgeoning threat of comprehensive GPS tracking. The government’s four-week, warrantless surveillance of Antoine Jones, he concluded, “surely crossed” the line and, for Fourth Amendment purposes, constituted a search. Alito was content to mark that boundary and reserve for the future “more difficult questions.”

Jones evidenced Alito’s taste for a slow and cautious approach that links constitutional law to our society’s shifting expectations and values. His opinion dotes on the details of new technology, portraying them with a mix of awe and worry. Alito does not seem perturbed, in general, by weaker privacy protections; he dissented in Jardines, seeing no search in the police deploying Franky to sniff for drugs. But he cares deeply about the Court’s institutional role in managing our transition toward a world in which privacy looks very different. And he is willing to undertake the daunting task of altering Fourth Amendment law—slowly and carefully—to keep it in step with the times.

*   *   *

While Alito dissented in Jardines, Scalia’s majority divided against itself. In a separate writing joined by Ginsburg and Sotomayor, Kagan distanced herself from Scalia’s property-based majority opinion. As she explained, “The Court today treats this case under a property rubric; I write separately to note that I could just as happily have decided it by looking to Jardines’ privacy interests. A decision along those lines would have looked … well, much like this one.” She added, “It is not surprising that in a case involving a search of a home, property concepts and privacy concepts should so align.” After all, “the sentiment ‘my home is my own,’ while originating in property law, now also denotes a common understanding—extending even beyond that law’s formal protections—about an especially private sphere.”

Kagan rarely writes separately and does so only with clear goals in mind. In Jardines, it’s likely that she wanted to ensure that Scalia’s rekindling of originalism and property analysis in Jones and Jardines would not jeopardize Katz. When the Court issues enough opinions that purport to remain faithful to one way of doing things but actually do something else, there is always a risk that someone will come along and say, “Well, the logic of our recent rulings really does mean that we must adopt a different rule.” Plainly concerned that Scalia might try to pull off such a coup d’état, dethroning Katz and its emphasis on evolving, reasonable expectations, Kagan strategically deprived him of a proper majority for his Olmstead-style reasoning. At the same time, she proposed some common ground for Scalia and Alito in a moment of doctrinal fracture, thus suggesting a possible path toward reconciliation in future privacy cases.

Whereas Kagan concurred in Jardines to build common ground, Sotomayor concurred in Jones to chart a bold new frontier. Although she provided Scalia with a fifth vote for his majority, she also wrote her most adventuresome opinion yet as a member of the Roberts Court. GPS monitoring, she emphasized, is uniquely dangerous: it “generates a precise, comprehensive record of a person’s public movements that reflects a wealth of detail about her familial, political, professional, religious, and sexual associations.” She went on to observe that GPS data are searchable, cheap, and surreptitious, and thus “evades the ordinary checks that constrain abusive law enforcement practices.” Rejecting a narrow view of privacy, she embraced a rich picture of privacy’s essential role in our lives, including its importance to “associational and expressive freedoms” and its effect on “the relationship between citizen and government.”

In a bold move, Sotomayor suggested that the Court take all this into account as part of its Katz analysis. “I would ask,” she elaborated, “whether people reasonably expect that their movements will be recorded and aggregated in a manner that enables the Government to ascertain, more or less at will, their political and religious beliefs, sexual habits, and so on.” She added, “I would also consider the appropriateness of entrusting to the Executive, in the absence of any oversight from a coordinate branch, a tool so amenable to misuse, especially in light of the Fourth Amendment’s goal to curb arbitrary exercises of police power … and prevent a too permeating police surveillance.”

Finally, Sotomayor called for reconsideration of the third-party doctrine: “This approach is ill suited to the digital age, in which people reveal a great deal of information about themselves to third parties in the course of carrying out mundane tasks.… I would not assume that all information voluntarily disclosed to some member of the public for a limited purpose is, for that reason alone, disentitled to Fourth Amendment protection.” In words that seem especially salient in light of recent revelations about government spying, she expressed doubt that “people would accept without complaint the warrantless disclosure to the Government of a list of every Web site they had visited in the last week, or month, or year.”

This remarkable opinion plants the seeds of a very different and far more privacy-protective approach to the Fourth Amendment. Sotomayor does more than express abstract fears; she offers thoughtful justifications for judicial intervention. In the world as she imagines it, the warrant requirement—and thus the courts—would play a far greater role in overseeing and legitimizing government efforts to obtain and store our private information, whether for immediate analysis or for later inspection.

Jones and Jardines reveal a Court openly dissatisfied with the status quo. No justice even pretended that precedent afforded direct or workable answers to the complex questions prompted by these two cases, and Scalia, Alito, and Sotomayor offered very different ideas about how best to respond. When the Roberts Court does choose a path forward, its rulings will undoubtedly redefine the contours of our relationship with the government and the meaning of American privacy.

*   *   *

It could have been an episode from the television show Cold Case. In 2003, a man broke into a woman’s home in Maryland and raped her. The police could not identify him, but they obtained and preserved a DNA sample from the crime, then entered that sample into the Combined DNA Index System (CODIS), which connects DNA laboratories throughout the nation. Six years later, Alonzo King was arrested for assault after a witness identified him as the man who had menaced a group of people with a shotgun. Pursuant to Maryland law governing arrests for serious offenses, police used a cotton swab of King’s cheek to obtain a DNA sample. Four months later, after a private vendor tested it, police learned that King’s DNA matched the sample from the 2003 rape. King was convicted of rape and sentenced to life in prison. On appeal, he argued that the cheek swab was an unconstitutional search.

Maryland v. King, decided in 2013, forced the Court to address what limits, if any, the Constitution imposes on the creation of a national DNA database.47 Rarely have the stakes of a privacy case been higher. The stuff of fantasy and nightmares, a national genetic repository would centralize in government hands a staggering amount of information. Calling for a vast expansion of DNA collection, Cyrus Vance, the Manhattan District Attorney, has celebrated its unparalleled potential to “identify the guilty, exonerate the innocent, bring justice to crime victims and prevent additional crimes from occurring.”48 Others take a less sanguine view. In 2004, Judge Stephen Reinhardt of the Ninth Circuit Court of Appeals reminded us of “all of the dangers inherent in allowing the government to collect and store information about its citizens in a centralized place.”49 Recalling the Palmer raids in 1920, the roundup and internment of Japanese-Americans during World War II, J. Edgar Hoover’s use of FBI surveillance to terrorize civil rights leaders, and the midcentury witch hunt of suspected Communists, he concluded that “even governments with benign intentions have proven unable to regulate or use wisely vast stores of information they collect regarding their citizens.” More than any technology before it, DNA sampling brings into stark relief the frightening difficulty of striking a balance between liberty and security, privacy and order.

Of course, the Court does not deal with technologies in the abstract. King addressed Maryland’s scheme, which required officers to perform a cheek swab to obtain DNA from all people arrested for serious offenses. In the course of briefing and argument, however, the Court encountered many related issues: Can states require that all citizens submit DNA samples or only certain people, such as those arrested for particularly serious crimes? Must the government destroy DNA samples after entering them into CODIS and, if not, what other uses may it make of that stored DNA? Do privacy interests require the deletion of genetic records if an arrestee is released?

Faced with all these issues, the Court walked a path unlike the one it followed in Jones. Rather than meditate broadly about the future of the Constitution, it offered an opinion that, at first glance, seems steadfastly narrow.

Kennedy, joined by Roberts, Thomas, Breyer, and Alito, held in King that using a cotton swab to collect King’s DNA did not violate his Fourth Amendment rights. The fundamental issue Kennedy addressed is whether the police must obtain a warrant based on individualized suspicion before collecting DNA or whether a general practice of swabbing all people arrested on suspicion of committing a serious crime is permissible. Fully aware that a warrant requirement could defeat widespread, involuntary collection of DNA, Kennedy held that Maryland did not need a warrant. He reasoned that, even though warrants based on individualized suspicion of wrongdoing are typically required when police undertake searches to solve crimes, the police do not need a warrant when they search for other reasons. These “special needs” searches include the warrantless scans we have all experienced at airports. When police search for reasons other than solving a crime, the Fourth Amendment requires only that the law enforcement interests at stake outweigh the individual privacy interests invaded.

The first question, then, was why Maryland collected DNA. Kennedy answered by exalting Maryland’s interest in “identification,” defined as “the need for law enforcement officers in a safe and accurate way to process and identify the persons and possessions they must take into custody.” This interest, he maintained, drove the whole Maryland program, not an interest in solving crimes. Kennedy also emphasized that arrestees have diminished expectations of privacy and that Maryland police have little discretion in deciding when to collect DNA—factors that he linked to other “special needs” cases. Thus, Kennedy held, Maryland did not need any warrants. It just needed to win the balance of competing interests.

Starting with law enforcement’s side of the equation, Kennedy highlighted the importance of identifying arrestees. This interest, he explained, includes information about an arrestee’s “past conduct” and “criminal history.” Armed with such knowledge, “police can ensure that they have the proper person under arrest and that they have made the necessary arrangements for his custody.” He added, “Just as important, they can also prevent suspicion against or prosecution of the innocent.” (This Court’s concern for innocence, however, has its limits; in 2009, Kennedy joined a conservative majority to hold that inmates have no right to testing of DNA that may prove their innocence.50) Kennedy clinched his argument with an analogy to fingerprinting: both technologies facilitate identification, and “the additional intrusion upon the arrestee’s privacy [in taking DNA] beyond that associated with fingerprinting is not significant.”

Kennedy described King’s privacy interests as comparatively meager. A cheek swab is a “minimal” intrusion, he argued, especially for arrestees with reduced privacy rights. Turning to the DNA sample, he emphasized that the CODIS genetic loci “come from non-coding parts of the DNA that do not reveal the genetic traits of the arrestee” and that the DNA is not tested in any other way. Finally, he approvingly noted that Maryland law protects against the collection of DNA for reasons other than identification.

Carefully weighing these law enforcement and individual privacy interests, Kennedy concluded that “DNA identification of arrestees is a reasonable search that can be considered part of a routine booking procedure.”

In a scathing dissent joined by Ginsburg, Sotomayor, and Kagan, Scalia tore into Kennedy’s central premise: “The Court’s assertion that DNA is being taken, not to solve crimes, but to identify those in the State’s custody, taxes the credulity of the credulous.” In Scalia’s view, Maryland’s unmistakable goal in collecting DNA samples was to solve crimes, and it is a bedrock principle that “the Fourth Amendment forbids searching a person for evidence of a crime when there is no basis for believing the person is guilty of the crime or is in possession of incriminating evidence.” The Court should therefore never have engaged in a general “reasonableness” analysis. Instead, he exclaimed, it should have insisted that Maryland support its crime-solving searches with individual warrants, each supported by probable cause sufficient to justify a DNA test.

Scalia challenged Kennedy on several fronts. First, he took issue with Kennedy’s capacious definition of Maryland’s interst in “identification.” To Scalia, Kennedy had demolished the line between investigating unsolved crimes and “the normal sense” of identification, which “would identify the author of Introduction to the Principles of Morals and Legislation as Jeremy Bentham.” Second, Scalia pointed out that the DNA sample wasn’t actually used to identify King. Indeed, it took Maryland four months to process the DNA sample, partly because state law barred DNA testing until after King was arraigned. “Does the Court,” Scalia artfully wondered, “really believe that Maryland did not know whom it was arraigning?” In truth, Scalia observed, “if anything was ‘identified’ at the moment that the DNA database returned a match, it was not King—his identity was already known.… Rather, what the [match] ‘identified’ was the previously-taken sample from the earlier crime. That sample was genuinely mysterious to Maryland.” It was thus absurd, Scalia concluded, to think that the real goal was the arrestee’s identification. Nor was Scalia impressed by Kennedy’s fingerprint analogy; DNA, he observed, takes far longer than fingerprints to analyze. For now, and likely for at least the near future, DNA cannot seriously be described as a quick identification tool.

To Scalia, Kennedy’s majority used a wholly disingenuous description of Maryland’s program to short-circuit the Fourth Amendment, all in service of cracking more cases. In his view, King boiled down to a choice the framers made long ago: “Solving unsolved crimes … occupies a lower place in the American pantheon of noble objectives than the protection of our people from suspicionless law-enforcement searches.” Recalling the dark history of royal abuses that gave rise to the warrant requirement, Scalia marked his “doubt that the proud men who wrote the charter of our liberties would have been so eager to open their mouths to royal inspection.” In closing, he wrote, “I therefore dissent and hope that today’s incursion upon the Fourth Amendment … will some day be repudiated.”

At one level, for all of Scalia’s fireworks, King was a narrow case. The Court decided that Maryland’s program was about identification, not fighting crime. It then balanced the competing values at issue and reached a result that would be subject to change as the uses of DNA evolved. Read this way, King deals mainly with how to describe the goal of one DNA collection program in relation to familiar Fourth Amendment law and in the midst of rapid technological change.51

This reading accords with Kennedy’s stated reluctance to issue broad pronouncements on privacy rights. In a recent case about searches of public employee text message records, he advised caution: “The judiciary risks error by elaborating too fully on the Fourth Amendment implications of emerging technology before its role in society has become clear.”52 Noting that the roles of cell phones and text messaging in American society are still in flux, Kennedy added, “Prudence counsels caution before the facts in [this] case are used to establish far-reaching premises that define the existence, and extent, of privacy expectations enjoyed by employees when using employer-provided communication devices.” A similar concern may have shaped his decision not to offer wide-ranging commentary on DNA databases in King.

Nonetheless, King is a landmark opinion. In its first case addressing a DNA database, the Court upheld the program and did not even suggest that Maryland’s law presented a close question. It thereby set an encouraging constitutional mood, signaling to lower courts and policy makers that the Constitution will not stand broadly in the way of DNA collection. Because constitutional law may previously have chilled innovation and cast a pall of illegitimacy over DNA programs, King likely will boost the recent trend favoring rapid expansion of CODIS. This trend has already led more than half the states to collect DNA from some arrestees.53 To those who fear such databases, viewing in them the terrors of Big Brother, King is a disaster. But to those who see a potentially remarkable boost in the fight against crime, King is—as Alito suggested at oral argument—“perhaps the most important criminal procedure case that [the] Court has heard in decades.”

King is so important partly because the majority’s insistence that the Maryland program is really all about identification is hard to accept. Surely it was not by coincidence that Maryland’s lawyer opened her argument at the Court by stating, “Since 2009, when Maryland began to collect DNA samples from arrestees charged with violent crimes and burglary, there have been 225 matches, 75 prosecutions and 42 convictions.” (Scalia promptly jabbed back, “Well, that’s really good. I’ll bet you if you conducted a lot of unreasonable searches and seizures, you’d get more convictions, too.”) Kennedy dealt with Maryland’s openly expressed concern with solving crimes by shoehorning it into the “identification” interest; he reasoned that a suspect’s past criminal acts are part of his “identity.” This controversial move will make it very difficult in the future to separate a state’s interest in identification from its interest in solving crimes—and will thus bar judges from imposing the limits on police officers embodied in a warrant requirement.

Even King’s seeming narrowness is actually a powerful statement in its own right. Kennedy barely acknowledged the concerns of those who deem DNA collection a threat to liberty. His opinion said little about what it means under the Constitution to permit vast, state-operated DNA databases in our democratic society. Nor did it address worries that lawmakers may not fairly balance privacy and security when they build massive DNA databases with samples taken mainly from arrestees, a group that is disproportionately poor, undereducated, and black.54 If anything, the majority was unreservedly enthusiastic about the promise of this new technology, despite the warnings by Orwell, Kafka, and Huxley that lace so much writing about DNA databases. Scalia, in contrast, charged the majority with permitting a “genetic panopticon”—another reference to Jeremy Bentham, who described a prison in which a single guard could see any inmate at any time, leaving each to wonder when he was being watched.

Scalia’s charge has some force. No doubt intentionally, Kennedy made little effort to cabin the scope of his ruling. He said almost nothing about the Fourth Amendment requiring privacy safeguards, such as eventual expungement of DNA records, as a condition of permitting DNA databases. He narrowly described the privacy interests at stake, declining to acknowledge the risk of government abuse as a weighty concern. He set aside the fact that the noncoding loci taken for CODIS are sometimes used to match family members. And, most important, he did not explicitly limit his ruling to people arrested on suspicion of serious offenses, a point evidenced most clearly by his analogy of DNA collection to ordinary fingerprinting.

This last point led Scalia to issue a warning: “As an entirely predictable consequence of today’s decision, your DNA can be taken and entered into a national DNA database if you are ever arrested, rightly or wrongly, and for whatever reason.” He is likely correct. It may even come to pass that King will be invoked to justify DNA sampling of nonarrestees thought to have reduced expectations of privacy. Indeed, King could ultimately be but a brief stop along the road to DNA sampling of the entire population. Some people would deplore that development, but others would welcome it—either on crime-prevention grounds or because a database to which all Americans are subject is far more likely to generate meaningful political safeguards against abuse than is a database to which we consign only the powerless. The majority in King does not seem perturbed by the thought of a universal database—unlike in Jones, where Roberts imagined his own car being tracked and reacted with alarm. Although interpreting the sounds of silence in a judicial opinion is a treacherous task, King’s narrowness is obviously a considered message.

King will also alter the constitutional landscape in even subtler ways. In 2004, almost a decade before King, Chief Judge Kozinski described the slippery slope toward which rulings like King impel us: “When further expansions of CODIS are proposed, information from the database will have been credited with solving hundreds or thousands of crimes, and we will have become inured to the idea that the government is entitled to hold large databases of DNA fingerprints.… A highly expansive opinion…, one that draws no hard lines and revels in the boon that new technology will provide to law enforcement, is an engraved invitation to future expansion. And when that inevitable expansion comes, we will look to the regime we approved today as the new baseline and say, this too must be OK because it’s just one small step beyond the last thing we approved.… By then the line—never very clear to begin with—will have shifted. The fishbowl will look like home.”55 Fourth Amendment law protects privacy, but it also shapes what we think privacy means. In ways large and small, King orients us toward a future in which the Constitution says little about DNA databases.

Kennedy’s is not the last word, however. DNA databases remain subject to vigorous political debate. Privacy advocates warn of the potential for abuse and error, adding that it is anomalous for a democratic society to let the government store intimate information about our genome in secret warehouses and vast computer networks.56 Database enthusiasts retort that the state can protect against misuse, and that the unparalleled crime-solving and crime-preventing potential of this new tool demands that we deploy it.57 As battles over fundamental principles rage, practical disputes over the specific policies governing DNA collection and storage occupy legislators, police officers, and courts.58 Those issues extend beyond deciding whose DNA we will take, where we will store it, what uses we will make of it, and how we will guard it against hackers and abusive bureaucrats. They reach out to encompass the whole criminal justice system, since racial disparities in arrest rates, failure to collect crime-scene DNA, and backlogged crime labs all threaten the integrity of DNA databases.59 The future may bend toward expansive use of DNA, but American society still faces questions about making privacy real in that genetic panopticon.

King proves the wisdom of Chief Judge Kozinski’s admonition that “new technologies test the judicial conscience.”60 A precarious five-justice majority has opened the door to a new world of involuntary DNA collection, offering an opinion whose silence speaks volumes. Right or wrong, King will change the landscape of American privacy—even as it offers an invitation to democratic debate over the rules that govern these databases of human life.

*   *   *

In the wee hours of a Southern California morning in September 2007, Mission Control at NASA’s Jet Propulsion Laboratory (JPL) waited nervously as the team prepared for liftoff of the Dawn spacecraft at Cape Canaveral Air Force Station. It was a thrilling moment. A year before, NASA had canceled the mission for budget reasons, only to reauthorize it months later, at which point weather problems delayed liftoff several times. Finally, at about seven A.M. eastern standard time, Dawn began its years-long trip to reach what NASA called the “uncharted and distant worlds Vesta and Ceres,” two asteroids that may well reveal secrets about our solar system’s original formation.61

Earlier that same year, the people at NASA had other secrets on their minds. As a response to 9/11, the White House had ordered all federal agencies to conduct background checks on contract employees. Agencies like NASA had long required their direct hires to undergo complete background investigations, but NASA hadn’t extended that rule to contract workers. Now, at the Jet Propulsion Laboratory—a NASA facility staffed entirely with contract employees and operated by the California Institute of Technology—workers came face-to-face with intensive government investigations.

Although most of the paperwork was routine, some of the questions the forms asked were probing. One asked employees to disclose any illegal drug use in the past year. Another form was sent to the employees’ references and to previous landlords; it asked about “any adverse information” concerning “violations of the law,” “financial integrity,” “abuse of alcohol and/or drugs,” or “mental or emotional stability.” All responses to these forms were subject to the Privacy Act, which imposes limits on the government’s retention, use, and disclosure of personal information.

A group of scientists, engineers, and administrative personnel filed suit, arguing that the Constitution required the government to conduct its background checks with a more discerning eye. They did not assert that NASA had no business asking them anything at all; rather, they maintained that the government needed to show sufficiently compelling reason to pose such personal inquiries in its background investigations. But because questionnaires don’t count as searches under the Fourth Amendment, the employees had to look elsewhere in the Constitution for privacy protections.

They ultimately invoked an unwritten “right to informational privacy.” In two cases decided in the 1970s, the Court referred to a constitutional “interest in avoiding disclosure of personal matters.”62 Since then, most federal appellate courts have recognized that the Constitution limits the acquisition and disclosure of sensitive personal information by the government. They have reasoned that this right applies when people legitimately expect privacy—and that the government, in such cases, must show a compelling reason to violate those expectations and demonstrate its adoption of adequate safeguards against abuse. These informational privacy cases have arisen in a wide range of contexts, from the disclosure of an individual’s HIV status in public records, to mandatory disclosure of personal financial records by state senators, to the disclosure of nude photos of an assault victim taken by police, to state regulations requiring abortion clinics to disclose unredacted copies of all patient records.63 The NASA plaintiffs asked the Court to hold that their comprehensive background checks violated this right.

When NASA v. Nelson reached the Roberts Court in 2011, every justice voted to reject the employees’ claim.64 Writing for the majority, Alito explicitly assumed, without finally deciding, that an informational privacy right exists. But he then concluded that, under any understanding of the right, the employees could not show that it had been violated. The government, he explained, “has a strong interest in conducting basic background checks into the contract employees minding the store at JPL.” Courts must “keep those interests in mind when asked to go line-by-line through the Government’s employment forms.” And to Alito, the questions about drugs made perfect sense: “Like any employer, the Government is entitled to have its projects staffed by reliable, law-abiding persons who will efficiently and effectively discharge their duties.” The presence of protections against disclosure of this information to the public only made it clearer that the employees must lose.

It would be easy to infer from the Court’s unanimity that this was an easy case. But the employees had prevailed below: a unanimous three-judge panel saw merit in their claim.65 Addressing NASA’s request for “any adverse information” about JPL employees, Judge Kimberly Wardlaw of the Ninth Circuit Court of Appeals had concluded that there was no basis for this intrusive inquiry: “It is difficult to see how the vague solicitation of derogatory information concerning the applicant’s ‘general behavior or conduct’ and ‘other matters’ could be narrowly tailored to meet any legitimate need, much less the specific interests that [NASA has] offered to justify the new requirement.”

NASA was a hard case because laws requiring the disclosure of sensitive personal information as a condition of government employment pose a risk of constitutional injury. Both the Ninth Circuit and the Roberts Court displayed admirable sensitivity to that danger, even though they disagreed over whether NASA had crossed the constitutional line and whether to formally recognize a right to informational privacy.

In an opinion concurring only in the result, Scalia, joined by Thomas, tore into Alito’s analysis. Scalia thought NASA was an easy case because, in his view, the “right to informational privacy” simply doesn’t exist. “Like many other desirable things not included in the Constitution,” Scalia wrote, “‘informational privacy’ seems like a good idea—wherefore the People have enacted laws at the federal level and in the states restricting the government’s collection and use of information.” But, he continued, “it is up to the People to enact those laws, to shape them, and, when they think it appropriate, to repeal them.” Nearly always hostile to the recognition of rights not specifically listed in the Constitution, Scalia asserted that the employees sought to “invent a constitutional right out of whole cloth.” It was “farcical,” he added, to contend that “a right deeply rooted in our history and tradition bars the Government from ensuring that the Hubble Telescope is not used by recovering drug addicts.”

Scalia took particular issue with Alito’s “never-say-never” approach, which avoided any final judgment on the existence of a right to informational privacy. He argued that the Court thereby “gets to pontificate upon a matter that is none of its business: the appropriate balance between security and privacy.” Scalia maintained that this made no sense: “The Court decides that the Government did not violate the right to informational privacy without deciding whether there is a right to informational privacy, and without even describing what hypothetical standard should be used to assess whether the hypothetical right has been violated.” Finally, Scalia warned, Alito’s opinion opened the door to confusing and absurd claims without providing the lower courts with any real guidance. “Thirty-three years have passed since the Court first suggested that the right may, or may not, exist,” Scalia protested. “It is past time for the Court to abandon this Alfred Hitchcock line of our jurisprudence.”

Alito left most of Scalia’s assault unanswered, though he did include an aggressive footnote listing other cases in which Scalia had assumed the existence of a right without finally deciding the question. If Alito had wanted to press the point, though, he could have advanced plenty of good arguments. Notwithstanding Scalia’s disdain, a right to informational privacy has deep roots in the Constitution’s text. It is often described by federal courts as a fundamental liberty interest protected under the Due Process Clause, just like the rights to abortion and same-sex intimacy.66 Viewed in this light, it can be conceptualized as part of our evolving traditions of liberty and respect for human dignity. It is also rightly understood as a product of the pattern formed by other amendments: the First, which safeguards expression and conscience; the Third, which keeps troops out of our homes; the Fourth, which watches over reasonable expectations of privacy; the Fifth, which thwarts self-incrimination; and the Ninth, which tells us that the Bill of Rights isn’t the final accounting of American freedom.67

In its parts and in sum, the Constitution may well guard a right to informational privacy. Even if it does, though, we can expect that statutes and regulations will usually strike an adequate balance between privacy and competing values. Only in special cases might the courts need to step in and impose constitutional limits. NASA wisely left room for the Court to breathe new life into this dimension of the Constitution, recognizing that the demands of our information era may call upon it to revisit the subject again.

*   *   *

“As nightfall does not come at once, neither does oppression. In both instances, there is a twilight when everything remains seemingly unchanged. And it is in such twilight that we all must be most aware of change in the air—however slight—lest we become unwitting victims of the darkness.”68 Justice William Douglas served on the Court from 1939 to 1975 and had more than a passing familiarity with threats to liberty. He knew that values like privacy are not lost suddenly; they wither and weaken over time, buffeted by changed politics and culture until we forget why they once seemed so vital. By the time they fall, it’s easy to pronounce their loss inevitable or desirable.

Our experiences of privacy shape our beliefs about where we should expect it and why we should value it. Those experiences, in turn, are defined as much by government and corporate action as by our own choices. In that great struggle for privacy’s soul, the Roberts Court will never have the final word. Its decisions are nonetheless of great moment. By deciding when the government may intrude upon our privacy, the Court crafts law that helps define the relationship between governed and government. By reminding us of the core values at stake in debates over privacy, the Court calls upon our better angels and steers our social dialogue toward shared principles. By stepping gingerly into a fast-changing world, the Court allows room for democracy to function and affords itself time to think carefully before reinterpreting the Constitution.

Justice Oliver Wendell Holmes Jr. was known to quip, “If my fellow citizens want to go to Hell I will help them. It’s my job.”69 Fair enough. Courts can’t save a nation from itself. The Roberts Court, though, doesn’t have the luxury of nihilism. It must create new constitutional law to deal with the new technologies that make possible such marvels as GPS tracking, DNA swabs, and text messages. And as it does so, it tinkers with the deep architecture of privacy that shapes our lives in countless and often mysterious ways.