Hedrick Smith reports on the government's post-9/11 domestic-surveillance efforts, including the controversial NSA eavesdropping program; and a December 2003 FBI data sweep of Las Vegas vacationers. Included: insights from former AT&T technician Mark Klein; former FBI assistant director Larry A. Mefford; former CIA senior counsel Suzanne Spaulding; and Peter Swire, a Clinton-administration privacy adviser.