The Supreme Court on Monday agreed to decide whether law enforcement authorities, armed with a valid search warrant from a federal judge, can demand that the US tech sector hand over data that is stored on overseas servers. In this case, which is now one of the biggest privacy cases on the high court's docket, the justices will review a lower court's ruling that US warrants don't apply to data housed on foreign servers, in this instance, a Microsoft server in Ireland.

The US government appealed, contending it has the legal right, with a valid court warrant, to reach into the world's servers with the assistance of the tech sector, no matter where the data is stored.

The case has huge foreign policy ramifications as well. Federal authorities sometimes demand that the US tech sector comply with court orders that conflict with laws of countries where the data is housed.

The dispute the Supreme Court chose to consider centers on the US government having obtained a valid warrant for e-mail messages as part of a drug investigation. Microsoft challenged the warrant and convinced a federal appeals court that US law does not apply to foreign data.

In agreeing to hear the case, the justices did not comment on their reasoning.

All the while, Congress is mulling legislation to enable the federal government to negotiate reciprocity agreements with like-minded foreign nations to give each side a right to data on foreign servers—with a valid warrant.

In its appeal to the high court, meanwhile, the US government said that the US tech sector should turn over any information requested with a valid court warrant. It doesn't matter where the data is hosted, the government argues. What matters, the authorities maintain, is whether the data can be accessed from within the United States.

Brad Smith, Microsoft's chief legal officer, said in a Monday blog post following the high court's announcement: "If U.S. law enforcement can obtain the emails of foreigners stored outside the United States, what's to stop the government of another country from getting your emails even though they are located in the United States?"

No oral argument date was immediately set.