If passed, legislation will protect foreign data from Uncle Sam.
Microsoft has applauded the introduction of a bill in the US Senate this week that limits police access to digital communications stored abroad.
The move follows the company’s legal dispute with the American government over its demand that the company hand over emails stored in its Irish facility in Dublin, in connection with a drug case.
Brad Smith, executive VP of legal and corporate affairs at Microsoft, said: "This bill proposes a more principled legal blueprint for balancing law enforcement needs with consumer privacy rights.
"It also creates an important model that will help advance the international conversation that is so critically needed."
The Law Enforcement Access to Data Stored Abroad (Leads) Act will allow US officials to obtain a search warrant for extraterritorial data only if it belongs to a US citizen, permanent US resident, or company incorporated in the US.
If a court finds that the warrant violates data laws of the state where the data resides it will be obliged to refuse or modify the request, a pertinent fact in Microsoft’s case given the advice of a former Irish minister of justice that data extradition required the approval of an Irish judge.
Chris Coons, a Delaware senator who sponsored the bill, said: "The government’s position that [Electronic Communications Privacy Act] warrants do apply abroad puts US cloud providers in the position of having to break the privacy laws of foreign countries in which they do business in order to comply with US law."
The ECPA previously extended protection from government wiretaps to computer data, having been confined to telephone calls before the bill came in during October 1986.