Cheap fares, be they cheap airplane tickets or cheap vacation packages, do passengers no good if his or her name is on the governments no fly list. Once placed on this list the person is not allowed to board an airplane. The no fly list has gone from approximately 3,400 people at Christmas to about 6,000.
The no fly list is constantly changing as hundreds of analysts sift through a continuing stream of intelligence. The final decision is made by about six experts from the TSA (Transportation Security Administration). This is a very delicate process. Select too many people to go on this list and innocent travelers are subject to unwarranted hassles. Leave someone off the list and a terrorist might be allowed to board a plane.
Even though the process for placing people on the list has improved over time and technology is more sophisticated, the no fly list it remains a very imperfect way to fight terrorism. The list has fluctuated significantly over time and in 04 peaked at about 20,000 people.
There have been cases where passengers on the no fly list were allowed to fly. At times this is done to allow agents to track suspected terrorists while they are in the U.S. Any suspected terrorist might have his belongings and person go through extra screening and additional federal air marshals might be placed on the plane to scrutinize him during his flight.
The system is only as good as the information that has been inputted. In the case of the Nigerian terrorist who tried to blow up a Northwest plane on Christmas day, his name was submitted to TIDE (Terrorists Identities Datamart Enterprise) but because the information sent to the center was incomplete the terrorists fathers warnings were not connected to other partial pieces of information.
As a consequence analysts did not send the Nigerians name to the next tier of analysis at the Terrorist Screening Center, where he could have been placed on a no fly list or at least marked to be closely monitored.