Fact-check: The NSA and September 11th
By Justin Elliott, ProPublica

Hijacker Khalid al Mihdhar, foreground, passes through security at Dulles International Airport hours before American Airlines Flight 77 slammed into the Pentagon
In defending the NSA’s sweeping collection of Americans’ phone call records, Obama administration officials have repeatedly pointed out how it could have helped thwart the 9/11 attacks: If only the surveillance program been in place before Sept. 11, 2001, U.S. authorities would have been able to identify one of the future hijackers who was living in San Diego.
Last weekend, former Vice President Dick Cheney invoked the same argument.