As the hijackers checked in at Dulles International Airport on the morning of September 11, 2001, “Both [Khalid al-] Mihdhar and [Majed] Moqed were flagged by CAPPS [Computer-Assisted Passenger Prescreening System], but since Mihdhar had no checked luggage and Moqed wasn’t carrying any explosives, the procedures had no effect on their mission.”
– James Bamford, The Shadow Factory, Page 83