Microsoft heads back to court in data sovereignty row

Microsoft's continuing battle against the US government over emails stored in its Irish datacentre entered a new phase today, with the company heading to the Second Circuit Court of Appeals in New York.

For nearly two years Microsoft has been embroiled in a court case that could have a significant impact on US cloud providers in particular, but potentially technology companies worldwide, as well as significant ramifications for future diplomatic relations between the US and Europe.

The tech giant was served with a warrant by an unnamed US law enforcement agency (thought to be the FBI) in 2013, demanding access to the Outlook emails of a person of interest in an investigation into illegal drugs.

However, when Microsoft searched for the emails it found they were all stored in its North Europe datacentre in Dublin and argued that the warrant was therefore invalid.

Judge Loretta Preska of the US District Court in Manhattan disagreed however, and in April 2014 ruled it is "a question of control, not a question of the location of the information". Her ruling has since been upheld several times in the New York court district.

To date, however, Microsoft has refused to hand over the data and in September last year was found in contempt of court for failing to do so. However, as Microsoft had already begun appeal proceedings, it wasn't sanctioned.

In total nearly 100 organisations have issued friend-of-the-court briefs to the Second Court of Appeals in support of Microsoft, including other cloud and communications providers such as Apple, Cisco and Verizon, which said their business could be harmed if users feared their data could be accessed by the US government irrespective of their nationality or location.

A number of news organisations, including Fox News and the Washington Post, have also lent their support, claiming a ruling in favour of the government could give US law enforcement to access to journalists' notes anywhere in the world, as have the American Civil Liberties Union (ACLU), Electronic Frontier Foundation, and US Chamber of Commerce.

For its part, Microsoft has argued that, should it ultimately lose the case, it would also give foreign governments free rein to access the data of American citizens stored in the US.

If Microsoft loses its latest appeal, and any subsequent appeals, it has sworn to take the case all the way to the US Supreme Court.

However, Orin Kerr, a George Washington University law professor, told Politico: "I doubt it would get to the Supreme Court, because the Supreme Court looks for disagreements among circuits and this is the first case to reach the circuit level. Its novelty is working against it."