Hundreds and perhaps thousands of people have been subjected to the surveillance, according to government officials. Officials have privately credited the eavesdropping with the apprehension of Iyman Faris, a truck driver who pleaded guilty in 2003 to planning to blow up the Brooklyn Bridge. Bush said other plots have been disrupted as well.
"The activities I have authorized make it more likely that killers like these 9/11 hijackers will be identified and located in time," he said.