Mohammed al-Qahtani
Allegedly part of the original 9/11 plot, Saudi-born Mohammed al-Qahtani was denied entry to the U.S. before the attacks on suspicion he was trying to immigrate. Captured in Afghanistan in December 2001, he underwent protracted torture during his interrogations at Guantánamo. In May 2008 charges against him were dropped by the U.S. legal authority. New charges were introduced the following November, and al-Qahtani remains in custody.