The Role of Social Networks in the Evolution of Al Qaeda-Inspired Violent Extremism in the United States, 1990-2015 (2016)

"How do terrorists organize? According to the 9/11 Commission Report, it took a tight and complex organization to recruit and infiltrate the hijackers into the United States, and to plan and oversee the simultaneous hijacking of multiple airplanes. The investigation also concluded that the network was for the most part based abroad, and they found no evidence of substantial financial support for the hijackers from within the United States. There was, however, a local support network that had been years in the making and questions continue to arise about the presence of advance men who may have paved the way for the hijackers. The role of Anwar alAwlaki is a continuing mystery, for example. A Zelig-like figure, Awlaki turned up repeatedly as the hijackers moved around the country before the attacks. Was he or wasn’t he in on the 9/11 conspiracy?"