Google is fighting back against National Security Letters, the secretive, controversial requests for data from the US government that bypass the court process and come with a gag order. The company has filed papers in a case called In Re Google Inc. Petition to set aside Legal Process; while the documents are sealed, Bloomberg reported on the nature of the filing. No details are currently available on the request itself, but the move is significant — Google would be the most prominent company yet to challenge an NSL.

Google is likely to find a sympathetic ear; the judge assigned to the case is Susan Illston, who last month ruled National Security Letters unconstitutional and ordered the FBI to stop issuing them after a 90-day appeal period. Google recently began volunteering information on the thousands of NSL requests it has received, though the government prevented the company from going into too much detail. NSLs are still technically enforceable until Judge Illston's order comes into effect, but it's unclear to what extent the government is likely to do so.