The ACLU and Microsoft are not necessarily at odds in the case, but the ACLU made clear that its motivations are different from Microsoft's.
"The primary focus of Microsoft's claims is in ensuring that Microsoft be permitted to communicate to its customers about searches and seizures of their information," the ACLU's motion said. "Microsoft's commitment to providing notice is laudable, and its decision to file this suit is noteworthy for being the first of its kind. [But] while Movants have every reason to believe that Microsoft's policy will not change, that policy is not legally binding, and it is certainly not compelled by the Constitution."
In other words, the ACLU contended, absent its participation in the case, Microsoft could at some future point change its position on informing customers, even if it won the lawsuit, and leave the ACLU clueless about any data demand.
While that may be unlikely, some legal experts have said that Microsoft's lawsuit was largely motivated by business concerns, not solely on a commitment to customers.
Sign up for CIO Asia eNewsletters.