SAN FRANCISCO — Google, Facebook and Microsoft on Tuesday asked the government for permission to reveal details about the classified requests they receive for the personal information of foreign users.

They made the request after revelations about the National Security Agency’s secret Internet surveillance program, known as Prism, for collecting data from technology companies like e-mail messages, photos, stored documents, videos and online chats. The collection is legally authorized by the Foreign Intelligence Surveillance Act, which forbids companies from acknowledging the existence of requests or revealing any details about them.

Google for the first time publicly acknowledged it had received FISA requests and said it had complied with far fewer of the requests than it received. Facebook and Microsoft did not go as far as discussing requests they had received but, like Google, said they wanted to be able to publish information on the volume and scope of the government requests.

Christopher Soghoian, a senior policy analyst studying privacy, technology and surveillance at the American Civil Liberties Union, said that while he appreciated the statements from the companies, they were largely meant to save face with users and employees.