Microsoft successfully challenges FBI data request

Microsoft has scored a victory against the United States government and the Federal Bureau of Investigation by successfully challenging an official disclosure request, partially unsealed court documents have revealed.

The win was announced by Microsoft's top legal officer Brad Smith, who said it represents the company's committment to notifying business and government customers if legal orders related to their data are received.

Currently, the FBI is able to issue so-called national security letters (NSLs) with information disclosure requests to telcos and internet and online service providers, who in turn are automatically gagged by the orders.

NSLs were introduced in the US Patriot search and surveillance act after after the September 11 terrorist attacks in New York City, and the FBI has been accused in the past of abusing the powerful legal device.

The Microsoft customer account the FBI last year sought to access in an effort to obtain basic subscriber information belonged to an unnamed enterprise customer with an Office 365 account, the documents unsealed by a Seattle district court show.

The US government withdrew the NSL request in late 2013, after claiming to have obtained the information it needed "through lawful means from a third party, the customer, in a way that maintains the confidentiality of the investigation," the court documents note.

Microsoft had until now been barred from mentioning the request. Smith called the nondisclosure proviso of the NSL "unlawful" and said it violated Microsoft's right under the US Constitution to free expression, and prevented the company from notifying enterprise customers about legal orders for their data.

According to Smith, government requests for data from enterprise customers are "extremely rare" and Microsoft seldom has to go to court to challenge them.

In the rare cases Microsoft has had to go to court, the company has succeeded in redirecting the government to obtain the information required directly from the customers in question, Smith said.