The National Security Agency worked through telecommunications giant AT&T as part of a program to trace telephone calls from Al Qaida terrorists to the United States, according to a former company technician.
Mark Klein, who spent more than 22 years with AT&T in New York and California, said in January 2003 that NSA set up a room adjacent to an office in the AT&T central office on Folsom Street in San Francisco to route and screen public phone calls.
Additionally, in October 2003, Klein said he learned that the secret NSA room was used to tap into AT&Tís WorldNet Internet room, which included large routers, modems and other equipment.
Fiber optic cables from the NSA room tapped into the WorldNet Internet equipment by splitting off a portion of the light signal.
The circuits broken into were called Peering Links that connected WorldNet with other networks throughout the country and world.
Klein said the NSA equipment included a Narus STA 6400, known as a semantic traffic analyzer, used to sift through large amounts of data in the search for pre-programmed targets.
The U.S. government has filed a States Secret Privilege notice to prevent further disclosure of the wiretap details, according to a former intelligence official.
The terrorist surveillance program has produced valuable intelligence on Al Qaida communications, according to Gen. Michael Hayden, principle deputy director of national intelligence and President Bush's new nominee to head the CIA.