To learn more about different terrorist groups, visit the Terrorism Research Center (www.terrorism.com), Special Operations (www.specialoperations.com/Terrorism), or Terrorism: Questions & Answers (http://cfrterrorism.org/home). From these sites you can learn about different terrorist groups around the world, how they organize, what their goals may be, and how they typically launch an attack.
Most interesting is that none of these terrorist information sites mention how terrorist groups often evolve from hate groups to terrorists to political parties to ruling governments, as witnessed by the Palestine Liberation Organization (PLO) and later, Hamas.
Perhaps the real threat of terrorism is that any terrorist group could get themselves elected as a "legitimate" government and further their objectives using military soldiers, instead of terrorists, to attack and kill innocent civilians. When this happens, anyone who supports the violence perpetrated by their government will be no better than the terrorists they so loudly condemn.