The biggest names in tech - including eBay, Google, Microsoft, Amazon, Twitter, and AirBnB - are supporting Apple in its court battle with the FBI, which wants a court to force the Cupertino giant to unlock the iPhone used by one of the killers in the San Bernardino terrorist attack.

Around 40 companies and organizations, along with several dozen individuals, formed several groups to file court briefs against the United States government's legal arguments against Apple in a case that will test the limits of the authorities' access to personal data.  The FBI managed to get a order demanding Apple helps unlock an iPhone belonging to Syed Farook, who with his wife killed 14 people in the California city last December before police fatally shot them.

"These companies, which are often fierce competitors, have joined together to voice concern about the attempted government overreach in this case, which threatens the integrity and security of their products and privacy rights of consumers in general," said attorney Neal Katyal of the extremely high-powered international law firm of Hogan Lovells, which is representing tech companies in some of the briefs. 

Among the tech firms' criticisms is the FBI's reliance on earlier decisions written during the 1970s before the digital age, and the All Writs Act of 1789, which was written half a century before the dawn of the telegraph. 

"Now, 200 years later," reads the brief joined by Google, Microsoft, Facebook, Yahoo, Amazon, and ten others, "the government endeavors to reinterpret the All Writs Act as an open-ended source of new powers."

In order words, opening a locked cell phone is not exactly like opening a locked safe as the FBI insists.

Apple and the FBI will return to court on 22 March.

“These companies, which are often fierce competitors, have joined together to voice concern about the attempted government overreach in this case, which threatens the integrity and security of their products and privacy rights of consumers in general,” said Neal Katyal, a lawyer at Hogan Lovells for the tech companies