In papers filed late Monday, AT&T argued that confidential technical documents provided by an ex-AT&T technician to the Electronic Frontier Foundation shouldn't be used as evidence in the case and should be returned. The documents, which the EFF filed under a temporary seal last Wednesday, purportedly detail how AT&T diverts internet traffic to the National Security Agency via a secret room in San Francisco and allege that such rooms exist in other AT&T switching centers.

AT&T built a secret room in its San Francisco switching station that funnels internet traffic data from AT&T Worldnet dialup customers and traffic from AT&T's massive internet backbone to the NSA, according to a statement from Klein.

The company asked for a hearing Thursday to determine whether the documents could be used in the class-action lawsuit, whether they would be unsealed or whether the EFF would have to return them. The EFF filed a rebuttal, calling that time frame unworkable and accusing AT&T of not following normal court rules.

AT&T's lawyers also told the court that intense press coverage surrounding the case, including Wired News' publication of Klein's statement, was revealing the company's trade secrets, "causing grave injury to AT&T." The lawyers argued that unsealing the documents "would cause AT&T great harm and potentially jeopardize AT&T's network, making it vulnerable to hackers, and worse."