An FBI order, which was challenged by Microsoft and remained sealed in the Seattle federal court until last week, is now released revealing that FBI has requested Microsoft to disclose information regarding a particular subscriber of its Office 365 enterprise package.

The confidential order, dubbed National Security Letter, requests Microsoft to furnish “several categories of information” of a particular enterprise customer along with a non-disclosure provision.

Following the unsealing of the court documents, Brad Smith, Microsoft’s general counsel wrote in a blog post, “Last December I announced that Microsoft was committed ‘to notifying business and government customers if we receive legal orders related to their data. Where a gag order attempts to prohibit us from doing this, we will challenge it in court.”

Keeping its promise, the company took it to the federal court stating that the non-disclosure provision was “unlawful and violated [Microsoft’s] constitutional right to free expression.”

The allegations went on to state that the gag order could have lasted “an impermissible length of time” and that it violated the separation of powers clause of the US Constitution.

FBI withdrew the letter after the lawsuit was filed, barring chances of an investigation into the case and hence the challenge was dropped before an inquiry was made leading to assumptions that it might have obtained the data through other legal means.

Several tech companies have been receiving letters from the government in the past to provide data regarding prominent businesses. In the wake of revelations by the Edward Snowden, former NSA contractor, the companies have started disclosing such requests from the government.

“In those rare cases where we have received requests, we’ve succeeded in redirecting the government to obtain the information from the customer, or we have obtained permission from the customer to provide the data,” Smith said.

“We’re pleased with the outcome of this case, which validates our approach.”