Microsoft and Google are considering filing a lawsuit against the US government after discussions with the Department of Justice to allow them to reveal the number of data requests they receive broke down.
The technology giants are concerned about damage to their reputations as they cannot disclose the number of government requests for user information they must comply with.
Microsoft general counsel Brad Smith was quoted by Reuters as saying: "While we appreciate the good faith and earnest efforts by the capable government lawyers with whom we negotiated, we are disappointed that these negotiations ended in failure."
National Intelligence director James Clapper said in a statement: "FISA and national security letters are an important part of our effort to keep the nation and its citizens safe, and disclosing more detailed information about how they are used and to whom they are directed can obviously help our enemies avoid detection."
In June the two tech majors had filed suits seeking to divulge more information about user data requests made under the Foreign Intelligence Surveillance Act.