Microsoft did challenge government surveillance requests, and sort of won18
That places Microsoft on a short list of companies that have challenged these National Security Letters (NSLs) which are often accompanied by a gag order, so that the recipients cannot even acknowledge that the letter exist to begin with.
Recently, a telecom company challenged the government in California in 2011 and won, but the government is appealing the ruling so the parties involved have not been revealed. Google has been able to loosen the gag orders of the NSLs it receives and incorporates broad data about the requests received from the government in its transparency statements.
The situation with Microsoft is also obscure, but an NSL was received some time last year, and Microsoft objected on the grounds that the gag order violated its free-speech rights. While that matter got bogged down, the FBI, who issued the NSL, approached Microsoft’s customer (who used Office 365), and apparently got some of what it was looking for.
The ACLU, while questioning whether Microsoft would have defended an individual rather than a business client did acknowledge, “Microsoft deserves credit for this.”
Unfortunately, the disposition of NSLs means we know little about them. They are typically issued by the FBI and are specific in nature as to what information they are seeking and do not typically breach the threshold that would require a warrant. While that does not make NSLs any less controversial, they are not broad data gathering mechanisms attributed to NSA activity.
Whether or not more companies will stand-up to protect user privacy is still a matter for debate.
source: The Wall Street Journal