More of the biggest names in tech – including eBay, Google and Amazon have joined Twitter and AirBnB in backing Apple in its court battle with the FBI.
The FBI has a court order demanding Apple helps unlock an iPhone belonging to the gunman behind the San Bernardino terror attack, Syed Rizwan Farook.
Farook and his wife killed 14 people in the California city last December before police fatally shot them.
Family members of some victims have backed the FBI’s order.
Two groups of tech giants have now filed an amicus brief, which allows parties not directly involved in a court case, but who feel they are affected by it, to give their view.
Apple has appealed against the court order, arguing that it should not be forced to weaken the security of its own products.
Since a software update released in September 2014, data on Apple devices – such as text messages and photographs – has been encrypted by default.
This prevents anyone without the owner’s four-digit passcode from accessing the handset’s data. If 10 incorrect attempts at the code are made, the device will automatically erase all of its data.
No-one, not even Apple, is able to access the data. But the FBI has asked the tech company to help it circumvent the security by altering Farook’s iPhone.
The agency wants it to do things: first change the settings so unlimited attempts can be made at the passcode without erasing the data; and second help implement a way to rapidly try different combinations to save tapping in each one manually.
Apple has argued that the move would jeopardise the trust it has with its customers and create a backdoor for government agencies to access customer data.
Twitter, AirBnB, Ebay, LinkedIn and Reddit are among a group of 17 major online companies to have formally backed Apple in its court dispute with the FBI.
Another group have filed a separate joint amicus brief. These include Amazon, Cisco, Facebook, Google, Microsoft, Mozilla, Pinterest, Snapchat, WhatsApp and Yahoo.
Intel and AT&T have also filed separate briefs.
Salihin Kondoker, whose wife survived being shot three times in December’s terror attack, has also filed a brief supporting Apple.
But family members of some other victims will jointly back the FBI’s order, Reuters reported.