A US court has ordered Google to hand over emails stored outside of the country to the FBI

Does the US government have the power to order American companies to hand over data stored on servers outside of the country? That's the question at the heart of a legal battle between Google and the FBI.

A US judge has ordered Google to comply with search warrants seeking customer emails stored outside the United States - even though a federal appeals court reached an opposite conclusion in a similar case involving Microsoft.

On Friday, US Magistrate Judge Thomas Rueter in Philadelphia ruled that transferring emails from a foreign server so FBI agents could review them locally as part of a domestic fraud probe did not qualify as a seizure.

The judge said this was because there was "no meaningful interference" with the account holder's "possessory interest" in the data sought.

"Though the retrieval of the electronic data by Google from its multiple data centers abroad has the potential for an invasion of privacy, the actual infringement of privacy occurs at the time of disclosure in the United States," Rueter wrote.

Google, referring to the Microsoft case, said in a statement that it planned to appeal. "The magistrate in this case departed from precedent, and we plan to appeal the decision," the Californian company said. "We will continue to push back on overbroad warrants."

The ruling came less than seven months after the 2nd U.S. Circuit Court of Appeals in New York said Microsoft could not be forced to turn over emails stored on a server in Dublin, Ireland that U.S. investigators sought in a narcotics case.

That decision, in July 2016, was welcomed by dozens of technology and media companies, privacy advocates, and both the American Civil Liberties Union and U.S. Chamber of Commerce. On Jan. 24, the same appeals court voted not to revisit the decision. But the four dissenting judges called on the U.S. Supreme Court or Congress to reverse it, saying the decision hurt law enforcement and raised national security concerns.

Both cases involved warrants issued under the Stored Communications Act, a 1986 federal law that many technology companies and privacy advocates consider outdated.

In court papers, Google said it sometimes breaks up emails into pieces to improve its network's performance, and did not necessarily know where particular emails might be stored.

Relying on the Microsoft decision, Google said it believed it had complied with the warrants it received, by turning over data it knew were stored in the United States.

Google receives more than 25,000 requests annually from U.S. authorities for disclosures of user data in criminal matters, according to Rueter's ruling.

The cases are In re: Search Warrant No. 16-960-M-01 to Google and In re: Search Warrant No. 16-1061-M to Google, U.S. District Court, Eastern District of Pennsylvania, Nos. 16-mj-00960, 16-mj-01061.