Nearly everyone who uses the Web has run into those annoying little pictures of text that you’re supposed to read to prove that you’re a human being. They’re known as Completely Automated Public Turing Tests to Tell Computers and Humans Apart (CAPTCHAs). And they’ve been Public Enemy #1 for blind, low-vision, and dyslexic people for years.
In May 2008, Matt appeared with the creator of CAPTCHA, Luis von Ahn, on an episode of ACB Radio, a web radio show put on by the American Council of the Blind. What von Ahn had to offer to his audience was not a rousing defense of his creation but a thoughtful acknowledgment of what accessibility advocates have said all along: it’s not a cure for cancer, and its use comes at the cost of excluding an increasing number of real people from services they should be able to access. Go here to listen to the show: http://www.acbradio.org/archives/mainmenu/ml341.m3u.
In a world where people with good vision and reading ability (and really big monitors) can’t solve CAPTCHAs reliably, where black-hat hackers sell CAPTCHA crackers for spammers to create free email accounts, and where even the creator of the idea says it’s begun to outlive its usefulness, what do you think is happening? Surprisingly, in a lot of ways, it’s actually getting worse. Visual verification schemes are getting such a bad rap that Flickr has hundreds of uploads featuring hilariously unsolvable puzzles, as shown in Figures 5-3 through 5-5.
Figure 5-5. The answer must be under there somewhere (Source: http://flickr.com/photos/phygimus/2242915083/)
Could you imagine trying to solve one of these on your mobile phone’s display?
And some researchers have decided that the way to get themselves out of this hole is to keep digging. The latest approaches involve perceiving images, sometimes even in 3-D, that correspond to items like chairs and animals that we would recognize in real life. While researchers’ creativity may be unparalleled, they are still trying to solve the wrong problem.
Avoid using CAPTCHAs. If you have a spam problem of any size, there are better, more inclusive solutions out there. When even those few very large sites have come to their senses regarding the use of these schemes and focused their energy elsewhere, we should all take the hint.
For a more complete anti-CAPTCHA rant, Matt wrote a paper titled “Inaccessibility of CAPTCHA: Alternatives to Visual Turing Tests on the Web,”[18] which outlines the strategies involved in finding an approach that more directly (and inclusively) addresses the problems that most people turn to visual verification to magically solve.
Jared Smith provides additional techniques in “Spam-free accessible forms” at http://www.webaim.org/blog/spam_free_accessible_forms/.
That’s all there is for simple forms. Will it get any easier in the future? We hope so. In fact, in Chapter 9, we talk about two technologies that are already changing things for the better: Ajax and ARIA.