The lawsuit, filed Tuesday in San Francisco's federal district court, charges that AT&T has opened its telecommunications facilitiesand continues to "to assist the government in its secret surveillance of millions of ordinary Americans."
The Electronic Frontier Foundation, which filed the suit, says AT&T's alleged cooperation violates free speech and privacy rights found in the U.S. Constitution and also contravenes federal wiretapping law, which prohibits electronic surveillance "except as authorized by statute."
Kevin Bankston, an EFF staff attorney, said he anticipates that the Bush administration will intervene in the case on behalf of AT&T. "We are definitely going to have a fight with the government and AT&T," he said.
AT&T said Tuesday that it needed to review the complaint before it could respond. But AT&T spokesman Dave Pacholczyk told CNET News.com last week in response to a query about NSA cooperation: "We don't comment on matters of national security."
A Los Angeles Times article dated Dec. 26 quoted an unnamed source as saying the NSA has a "direct hookup" into an AT&T database that stores information about all domestic phone calls, including how long they lasted.
If the Bush administration does intervene, EFF could have a formidable hurdle to overcome: the so-called "state secrets" doctrine.
The state secrets privilege, outlined by the Supreme Court in a 1953 case, permits the government to derail a lawsuit that might otherwise lead to the disclosure of military secrets.
In 1998, the 9th Circuit Court of Appeals elaborated on the state secret privilege in a case where former workers at the Air Force's classified Groom Lake, Nev., facility alleged hazardous waste violations. When requested by the workers' lawyers to turn over information, the Air Force refused.
The 9th Circuit upheld a summary judgment on behalf of the Air Force, saying that once the state secrets "privilege is properly invoked and the court is satisfied as to the danger of divulging state secrets, the privilege is absolute" and the case will generally be dismissed.
The Bush administration also is defending a related lawsuit filed earlier this month by the American Civil Liberties Union, that says the surveillance was unconstitutional and illegal.
AT&T has 30 days to file a response, which could include a request that the case be dismissed or a motion for summary judgment.
CNET News.com's Anne Broache contributed to this report