At any stage, the process can lead to "horror stories" of mixed-up names and unconfirmed information, Travers acknowledged.

....In 2004 and 2005, misidentifications accounted for about half of the tens of thousands of times a traveler's name triggered a watch-list hit, the Government Accountability Office reported in September.

In other words, it's a vacuum cleaner. Some examples:

Sen. Ted Stevens (R-Alaska) said last year that his wife had been delayed repeatedly while airlines queried whether Catherine Stevens was the watch-listed Cat Stevens. The listing referred to the Britain-based pop singer who converted to Islam and changed his name to Yusuf Islam. The reason Islam is not allowed to fly to the United States is secret.

So is the reason Maher Arar, a Syrian-born Canadian, remains on the State Department's consular watch list. Detained in New York while en route to Montreal in 2002, Arar was sent by the U.S. government to a year of imprisonment in Syria. Canada, the source of the initial information about Arar, cleared him of all terrorism allegations last September -- three years after his release -- and has since authorized $9 million in compensation.

There's no adequate mechanism in place to get removed from the list.

A unit at the screening center responds to complaints, he said, but will not remove a name if it is shared by a terrorism suspect. Instead, people not on the list who share a name with someone listed can be issued letters instructing airline personnel to check with the TSA to verify their identity. The GAO reported that 31 names were removed in 2005.

31 out of thousands of complaints.