The National Security Agency has traced and analyzed large volumes of telephone and Internet communications flowing into and out of the United States as part of the eavesdropping program that President Bush approved after the Sept. 11, 2001, attacks to hunt for evidence of terrorist activity, according to current and former government officials.This has led to some speculation that the reason the Bush administration didn't even try to get FISA Court approvals is because what is going on here is not wiretapping in the ordinary sense, but data mining along the lines of the "Total Information Awareness" program that was supposedly shut down by Congress after public protest.
The volume of information harvested from telecommunication data and voice networks, without court-approved warrants, is much larger than the White House has acknowledged, the officials said. It was collected by tapping directly into some of the American telecommunication system's main arteries, they said.
What has not been publicly acknowledged is that N.S.A. technicians, besides actually eavesdropping on specific conversations, have combed through large volumes of phone and Internet traffic in search of patterns that might point to terrorism suspects. Some officials describe the program as a large data-mining operation.
Officials in the government and the telecommunications industry who have knowledge of parts of the program say the N.S.A. has sought to analyze communications patterns to glean clues from details like who is calling whom, how long a phone call lasts and what time of day it is made, and the origins and destinations of phone calls and e-mail messages.
Telecommunications companies, either voluntarily or under government duress, are apparently giving the government direct access to voice switches (and perhaps data switches or routers) to enable them to intercept any or all traffic passing through them, using automated tools to examine traffic patterns or content for "interesting" traffic.
Gary Farber has blogged on this at Amygdala. Noah Schactman at DefenseTech. Tim Sandefur has blogged on Robert Levy's criticism of the Bush administration's argument for warrantless wiretaps (FISA has a provision for warrantless wiretaps during the first 15 days after Congress declares war; thus if the September 18, 2001 Joint Resolution by Congress which authorized the President to use "all necessary and appropriate force" against the perpetrators of 9/11 counted as a declaration of war, warrantless wiretaps would only be allowed until October 3, 2001). Ed Brayton has more on that subject at Dispatches from the Culture Wars.
(Disclosure: I work in network security at a global telecommunications company which, to the best of my knowledge, is not participating in a program like what is described above.)