Video: PBS Confirms that NSA Could Have Prevented 9/11

Author James Bamford looked into the performance of the NSA in his 2008 book, The Shadow Factory, and found that it had been closely monitoring the 9/11 hijackers as they moved freely around the United States and communicated with Osama bin Laden’s operations center in Yemen. The NSA had even tapped bin Laden’s satellite phone, starting in 1996.