AT&T backs Microsoft's dispute over warrant for emails held abroad

AT&T is backing Microsoft in its challenge of a US search warrant for private email communications located in a facility in Dublin, Ireland.

The telecommunications company filed in a New York court asking permission to submit an amicus curiae brief in support of Microsoft. Described as a "friend of the court," an amicus curiae is not directly involved in a litigation but believes it may be impacted or has views on the matter before the court.

Along with Verizon, all three companies have expressed concern that the US government's demands for data held abroad could alienate overseas customers from placing their data with US providers, particularly after the disclosures of surveillance abroad by the US National Security Agency.