So how many terrorist plots have they stopped because of this program?

"Intelligence officers who eavesdropped on thousands of Americans in overseas calls under authority from President Bush have dismissed nearly all of them as potential suspects after hearing nothing pertinent to a terrorist threat, according to accounts from current and former government officials and private-sector sources with knowledge of the technologies in use.

Bush has recently described the warrantless operation as "terrorist surveillance" and summed it up by declaring that "if you're talking to a member of al Qaeda, we want to know why." But officials conversant with the program said a far more common question for eavesdroppers is whether, not why, a terrorist plotter is on either end of the call. The answer, they said, is usually no. Fewer than 10 U.S. citizens or residents a year, according to an authoritative account, have aroused enough suspicion during warrantless eavesdropping to justify interception of their domestic calls, as well....read on