"Considerable controversy continues to surround U.S. air passenger prescreening and terrorist watchlist checks. In the past, such controversy centered around diverted international flights and misidentified passengers. Another issue surfaced on Christmas Day 2009, when an air passenger attempted to ignite an explosive device on a Detroit-bound flight from Amsterdam. Although U.S. counterterrorism officials reportedly had created a record on the air passenger in the Terrorist Identities Datamart Environment (TIDE), which is maintained at the National Counterterrorism Center (NCTC), it does not appear that the NCTC ever nominated him for entry into the U.S. government's consolidated Terrorist Screening Database, which is maintained at the Terrorist Screening Center. Therefore, he would not have been placed on watchlists used by front-line, air passenger prescreening agencies, principally the Department of Homeland Security (DHS), Transportation Security Administration (TSA), and Customs and Border Protection (CBP)."
CRS Report for Congress, RL33645
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html