Microsoft Corp. and its allies have braced for a long battle in the courts and in Congress over a 1986 electronic communications law, as the technology giant fights a U.S. search warrant to give up customer data it has on a server in Ireland.

Speaking at Microsoft’s Washington, D.C., offices as part of a discussion on “Making the Legal System Compatible with the Cloud-Driven World,” a lawyer for the company, along with attorneys for Verizon Communications Inc., BSA | The Software Alliance and the Electronic Frontier Foundation, said they expect the Stored Communications Act dispute before a federal trial court in New York to face appellate court review, and they hope it will get the attention of lawmakers who can update the law.