Verizon and other telephone companies didn't protest when a secret surveillance court demanded that they turn over records on all of their customers.
In a letter to Senate Judiciary Committee leaders on Monday, Judge Reggie Walton of the Foreign Intelligence Surveillance (FISA) Court revealed that no telephone company or other service provider has ever resisted a court order under Section 215 of the Patriot Act.
The provision allows the government to seize business records if they are "relevant" to a terrorism investigation.
It is unclear what other information the NSA might be collecting under Section 215.
Revelations about the scope of the government's surveillance programs have left communications providers scrambling to reassure their customers that their private information is safe.
Google, Facebook, Yahoo and Microsoft all issued statements saying they would resist overly broad orders and fight for their customers' privacy rights.
Verizon, which received the order leaked by Snowden, said that it "continually takes steps to safeguard its customers' privacy" but is required to comply with legal orders.
The phone companies also complied with warrantless wiretapping during the Bush administration. Congress retroactively granted the companies immunity for their role in the program.
In his letter, Walton acknowledged that in 2007, Yahoo fought a FISA Court order issued under a different law, the Protect America Act. The court received briefings from both sides and issued a classified decision in 2008.
Recently, Google and Microsoft have filed motions with the FISA Court for permission to declassify how many users have been affected by the surveillance orders. Privacy advocates, including the American Civil Liberties Union and the Electronic Frontier Foundation, have also filed legal requests for more transparency.
Walton also disclosed details about how FISA Court judges review surveillance requests from the government. He said that although the court rarely rejects government requests, it often requires changes to the government's proposed surveillance.
Jameel Jaffer, deputy legal director for the ACLU, said Walton's letter shows the legal framework for surveillance is "fundamentally broken."
"The mechanisms that were meant to serve as checks against abuse remain entirely hypothetical, but the dragnet surveillance programs that have been exposed over the last few weeks are a very real and direct result of this systemic failure," he said in a statement.