Microsoft has filed a court challenge to a US government demand that it hand over emails from its data center in Ireland. That appears to be the first time a US corporation has opposed such an order, and Microsoft has been backed by the Electronic Frontier Foundation (EFF) and an amicus brief from Verizon. The US prosecutor heading the drug case in question said that if the objection succeeds, tech companies like Microsoft could stymie domestic cases by merely storing data overseas.