Microsoft, addressing persistent concerns that it has helped the US government gather customer information, says it does not provide direct access to e-mails, instant messages or Skype calls and refuses to grant agencies the ability to break its encryption.
It has written to US Attorney General Eric Holder seeking more freedom to disclose how it handles requests for customer data from national security organisations. Microsoft said such permission had been postponed. Company lawyer Brad Smith asked Holder to take action personally to permit Microsoft to reveal more on how many security requests it received and how it handled them.
"We believe the US constitution guarantees our freedom to share more information with the public, yet the government is stopping us," he said.
The appeal comes a week after The Guardian paper reported that Microsoft allowed US security agencies to circumvent encryption of Outlook e-mails and capture Skype online chats, citing leaked documents provided by whistle-blower Edward Snowden on the US government's surveillance programmes.
The world's largest software firm said there were "significant inaccuracies" in media reports last week and it did not allow any government direct or unfettered access to customers' e-mails, instant messages or data. Microsoft, Apple, Facebook and Yahoo have come under scrutiny since Snowden's revelations.
Microsoft said that while it was limited in what it could disclose, the company did not grant access to servers and only provided governments with specific information. That includes data from its SkyDrive cloud service.
"We do not provide any government with the ability to break the encryption, nor do we provide the government with the encryption keys," Smith said. "When we are legally obligated to comply … we pull the specified content from our servers."
Brian Fallon, Holder's spokesman, did not have an immediate comment on the letter.