(Bloomberg) — Apple Inc., Google and Amazon.com Inc. were among the tech leaders that rallied behind Microsoft Corp. in its battle to stop the U.S. government from conducting so-called sneak-and-peek searches of customer e-mails.

Microsoft and its supporters argue the very future of mobile and cloud computing is at stake if customers can’t trust that their data will remain private. A group of 11 technology firms including Google said Friday in its court filing that the federal law allowing the searches goes “far beyond any necessary limits” while infringing users’ fundamental rights.

“The government’s ability to engage in surreptitious searches of homes and tangible things is practically and legally limited," the companies said in the filing. “But the act allows the government to search personal data stored in the cloud without ever notifying an account owner that her data has been searched."

Delta Air Lines Inc. and BP America Inc. along with the U.S. Chamber of Commerce and other businesses also asked to join the case in support of Microsoft, saying the benefits of cloud computing won’t be realized if privacy rights aren’t protected against government surveillance. Those companies, some of which are Microsoft customers, include Eli Lilly & Co. and GlaxoSmithKline Plc. Twitter Inc. also sought to join the fray.

The Justice Department, Attorney General Loretta Lynch and their backers, defend the searches, saying they need digital tools to help fight increasingly sophisticated criminals and terrorists who are savvy at using technology to communicate and hide their tracks.

Mark Abueg, a Justice Department spokesman, didn’t immediately respond to a call seeking comment on the filings supporting Microsoft and whether the government was expecting any on its behalf.

The government said in its response to the lawsuit in July that Microsoft doesn’t have the authority to sue over whether its users’ constitutional protections against unlawful search and seizure are being violated. It argues the company has asked the court to rule on thousands of cases related to the dispute without considering the individual basis for each one.

Endpoint ‘Unclear’

Apple said in its filing that the frequency and volume of the government’s use of the gag orders are “virtually unlimited in practice because their endpoint is unclear.” In 2016, Apple said it has received almost 600 gag orders.

Fox News Network LLC, the Associated Press and 27 other news organizations asked in a separate filing Friday to join the case, saying restraints on disclosing warrants to e-mail users violate free-speech rights.

The American Civil Liberties Union, along with privacy groups such as the Electronic Frontier Foundation, are also seeking to file so-called friend-of-the-court briefs in support of Microsoft.

“It’s not every day that Fox News and the ACLU are on the same side of an issue,” Brad Smith, Microsoft’s chief legal officer, said in an e-mailed statement. “We believe the constitutional rights at stake in this case are of fundamental importance, and people should know when the government accesses their e-mails unless secrecy is truly needed.”

Microsoft has been fighting the U.S. over customer privacy and clandestine disclosures to investigators for more than two years. In July, the software maker persuaded an appeals court to overturn an order to hand over e-mails stored on servers in Ireland as part of a Manhattan drug prosecution.

Government Warrants

In the case before a federal judge in Seattle, Microsoft calls the 1986 Electronic Communications Privacy Act unconstitutional, citing its own First Amendment free speech rights and its customers’ Fourth Amendment right to know whether the government has searched or seized their property. Those very laws allow the U.S. to obtain electronic communications with a warrant and secrecy order if it would endanger their case or a person, the government contends.

Global trust in U.S. surveillance has waned since the disclosures of former CIA employee and security contractor Edward Snowden, to the point that companies now have to make overtures to consumers about their interest and ability to keep content secure, said Bloomberg Intelligence analyst Matt Larson.

“Microsoft wants to be able able to tell its customers that these types of proceedings are going on to protect their privacy," Larson said. “The end game for Microsoft here is to at least have the DOJ revisit its procedures when pursuing these warrants."

Microsoft alleges that in the 18 months leading up to the April complaint, it received more than 5,600 federal demands for customer data, about 2,600 of which were accompanied by secrecy orders that prevent Microsoft from disclosing searches to the affected customers.

Microsoft’s supporters include four former U.S. attorneys in Washington state and a former special agent in charge of the FBI’s Seattle office. They contend that secret searches are unconstitutional because “obtaining a warrant, but not disclosing it, nullifies an essential function of the warrant, which is to provide notice to the person who is the target of the search."