Microsoft on Monday welcomed new allies in its fight to avoid surrendering customer email stored in Ireland to federal prosecutors in the United States.

Ten legal briefs were filed with the Second Circuit Court of Appeals on behalf of 28 technology and media companies, 35 computer scientists, and 23 trade and advocacy organizations. The amicus briefs argue that the US government should not be able to use a US search warrant to demand that Microsoft produce data stored abroad.

A negative outcome of the case could undermine cloud computing services, something the technology industry has struggled to reinforce following the disclosures last year arising from documents leaked by Edward Snowden. Businesses and individuals will be reluctant to use cloud computing services if any government can demand data in any other country.

In December 2013, federal prosecutors asked for a search warrant to obtain the contents and the metadata of a Microsoft user account, pursuant to a narcotics investigation. The metadata was stored in the US, but the contents of the messages were stored in Dublin, Ireland. Microsoft refused to turn over the contents of the messages, arguing US authorities have no jurisdiction over data stored abroad

In April 2014, a federal judge disagreed and ordered Microsoft to turn over the emails. Microsoft then appealed to a New York district court and was denied again. The company's latest appeal brings the case to the Second Circuit Court of Appeals, one level below the Supreme Court.

Given that the Supreme Court agrees to consider less than 1% of appeals, Circuit Court decisions tend to set legal precedents.

Microsoft and companies that have joined its case in support -- including Apple, Amazon, AT&T, Cisco, Salesforce, HP, eBay, Infor, Rackspace, and Verizon -- believe that the US government should rely on established legal practice rather than attempt to enforce US law in a foreign country.