More and more fliers are finding that theyve been placed on the US governments terrorist watch list. Data revealed during a civil lawsuit shows that over 1.5 million have been added to the list over the past five years, reports the Associated Press. The terrorist watch list was first created back in 2003, and, according to the FBI, it allows officials at screening locations to positively identify known or suspected terrorists trying to obtain visas, enter the country, board aircraft, or engage in other activity. The government calls the list one of the most effective counterterrorism tools it has at its disposal.