The Electronic Frontier Foundation (EFF) has filed legal briefs and evidence supporting its motion for a preliminary injunction in its class-action lawsuit against AT&T.

After asking EFF to hold back the documents so that it could review them, the Department of Justice consented to EFF's filing them under seal -- a well-established procedure that prohibits public access and permits only the judge and the litigants to see the evidence.

"The evidence that we are filing supports our claim that AT&T is diverting Internet traffic into the hands of the NSA wholesale, in violation of federal wiretapping laws and the Fourth Amendment," said EFF Staff Attorney Kevin Bankston.

"More than just threatening individuals' privacy, AT&T's apparent choice to give the government secret, direct access to millions of ordinary Americans' Internet communications is a threat to the Constitution itself. We are asking the Court to put a stop to it now."

EFF's evidence regarding AT&T's dragnet surveillance of its networks includes a declaration by Mark Klein, a retired AT&T telecommunications technician, and several internal AT&T documents. This evidence was bolstered and explained by the expert opinion of J. Scott Marcus, who served as Senior Advisor for Internet Technology to the Federal Communications Commission from July 2001 until July 2005.

The internal AT&T documents and portions of the supporting declarations have been submitted to the Court under a tentative seal, a procedure that allows AT&T five court days to explain to the Court why the information should be kept from the public.

"The public deserves to know about AT&T's illegal program," said EFF Legal Director Cindy Cohn. "In an abundance of caution, we are providing AT&T with an opportunity to explain itself before this material goes on the public docket, but we believe that justice will ultimately require full disclosure."

The NSA program came to light in December, when the New York Times reported that the President had authorized the agency to intercept telephone and Internet communications inside the United States without the authorization of any court. Over the ensuing weeks, it became clear that the NSA program has been intercepting and analyzing millions of Americans' communications, with the help of the country's largest phone and Internet companies, including AT&T.

"Mark Klein is a true American hero," said EFF Staff Attorney Kurt Opsahl. "He has bravely come forward with information critical for proving AT&T's involvement with the government's invasive surveillance program."

In the lawsuit, EFF is representing the class of all AT&T residential customers nationwide.