UPDATE: The Microsoft Ireland Decision: U.S. Appeals Court Rules that ECPA Does Not Require Internet Service Providers To Produce Electronic Communications Stored Overseas [June 28, 2017] [open pdf - 129KB]
"On July 14, 2016, a panel of the United States Court of Appeals for the Second Circuit unanimously ruled that the United States government could not enforce a subpoena seeking Microsoft to retrieve emails stored on a server in Ireland. The case, Microsoft Corporation v. United States, could have important implications both for federal law enforcement efforts to obtain electronic communications stored overseas and privacy protections afforded to those communications. In what is commonly referred to as the Microsoft Ireland decision, the Second Circuit analyzed the jurisdictional reach of the Stored Communications Act, which was enacted in 1986 as Title II of the broader Electronic Communications Privacy Act (ECPA). Discussed in an earlier CRS Report, ECPA is the primary federal law dictating the methods the government may use to access stored electronic communications. The Microsoft Ireland case hinged on whether a particular provision of the Stored Communications Act, Section 2703, applied extraterritorially such that it allowed the government to obtain electronic communications stored outside the territorial jurisdiction of the United States."
CRS Legal Sidebar, June 28, 2017
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html