On March 11, 2002, a letter from the U.S. Immigration and Naturalization Service stated that 9/11 hijackers Mohamed Atta and Marwan al-Shehhi had been approved for student visas to study flying. “There was only one problem: Six months earlier Atta and al-Shehhi were at the controls of the two hijacked commercial airliners that hit the World Trade Center towers. The embarrassing incident highlighted that the Immigration and Naturalization Service (INS) has been unable to keep track of foreigners in the United States–even the most notorious mass murders in American history.”
– Bill Gertz, Breakdown, Pages 141-142