Microsoft has claimed that - unlike some competitors - it doesn't provide US intelligence agencies with direct access to users' e-mails, instant messages or Skype calls and refuses to grant agencies the ability to break its encryption.
In a letter to US Attorney General Eric Holder, Microsoft asked for permission to reveal more information about its relationship with such agencies.
Microsoft, Apple, Facebook and Yahoo have come under scrutiny since former US National Security Agency contractor - and current fugitive - Edward Snowden said last month that the NSA is collecting user data from IT companies
Microsoft said that, while it's limited in what it can disclose, the company doesn't grant access to servers and only provides governments with specific information about requests. That includes data from its SkyDrive cloud service.