Bill Binney's Thinthread program at NSA had built-in protection for US citizens, but Michael Hayden and gang scrapped it for the boondoggle Pathfinder Project, which had no such protection. They later proved that Thinthread would have predicted the 9/11 attacks. Pathfinder did not and a few years later Pathfinder was ended, but its supporters kept their money.
Thomas Drake, a senior executive at NSA, quoted Maureen Baginsky: "9/11 is a gift to NSA. We're gonna get all the money we need and then some."