Nidal Hasan is only the latest in a series of Western Muslim terror suspects inspired by Anwar al-Awlaki, a web-savvy New Mexico-born radical cleric who preaches jihad in American-accented English. Devotees of Awlaki's sermons include a conspirator in the 2007 plot to attack Fort Dix and a group of Canadian Muslims who plotted to behead their prime minister; he also served as imam to several September 11 hijackers, the New York Times reports.
Awlaki, who corresponded with Nidal Hasan, "condenses the al-Qaeda philosophy into digestible, well-written treatises," according to a counterterrorism expert. Though Awlaki tells Muslims "who to kill, and why," his writings don't teach anyone how to build a bomb, and are First Amendment-protected speech. Making the question of what to do about pro-terror clerics like Awlaki even more complex, intelligence analysts view websites like his as valuable counterterrorism tools, as those who visit such sites can be tracked.
(Read more Anwar al-Awlaki stories.)