Apple's biggest competitors filed a joint legal brief today in support of the company in its ongoing encryption battle with the US government.
In a show of solidarity and unity in their position, Amazon, Facebook, Google, Microsoft and 15 other major tech firms filed a single amicus brief to side with their rival and outline why a decision in the government's favor would be harmful to the industry and consumers.
"Amici often compete vigorously with Apple - and with each other," the brief reads. But, with "one voice," the group is speaking out "because of the singular importance of this case" and because of the trust their customers place in them to keep their data safe and secure.
As Apple and others have expressed, the group shares in the grief and outrage at the San Bernardino terrorist attack that killed 14 people, say they have no sympathy for the terrorists, and support lawful investigation into the crime.
But the participants don't consider the government's effort to "commandeer a company's own engineers to undermine their products' data security features" lawful.
At the heart of the group's brief is an evisceration of the All Writs Act (AWA), which the government is basing its request that Apple build a special software to circumvent its own security measures on.
The companies call the government's interpretation of the AWA "unprecedented and unnecessary" and refer to the 227-year-old law as a "limited, 'residual' source of federal court authority."
Enacted 50 years before the invention of the telegraph and last significantly amended in 1911, it's too narrow to be applied in the way the government wants in a case involving 21st Century technology, they say. They cite a ruling that came down on Monday in which a court rejected the government's efforts to use the AWA to force Apple to unlock an iPhone in another case.
More side with Apple
The Amazon, Google, Microsoft et al filing is one of several amicus briefs (briefs from outside parties who have an interest in a case) filed with a court asking it to throw out a court order that would compel Apple to assist the FBI in unlocking an iPhone by creating a special software.
Apple is resisting building the software because it views it as a backdoor into the iPhone that could put hundreds of millions of users at risk. It's also concerned about setting a precedent the government could use in future requests to Apple as well as other companies.
The FBI is demanding the software be built so it can unlock the iPhone 5C used by one of the San Bernardino terrorists. It wants to get as much information from the phone as possible, though it's not sure what's on there or if it will be of value to the investigation.
Another group including Twitter, LinkedIn, Airbnb, Reddit and 13 other companies filed an amicus brief with the court earlier Thursday.
The Twitter briefing also strikes at the government's invocation of the AWA, saying the law doesn't grant it the authority to force a private company to re-write its own code and help law enforcement in the way the government is seeking.
"This extraordinary and unprecedented effort to compel a private company to become the government's investigative arm not only has no legal basis under the All Writs Act or any other law, but threatens the core principles of privacy, security and transparency that underlie the fabric of the internet," it reads.
If the government's demands are met, the brief notes, it would "set a dangerous precedent."
Intel and US carrier AT&T filed individual briefs Thursday. A number of advocacy groups, including the American Civil Liberties Union, filed briefs earlier this week.
Apple has compiled links to many of the briefs as well as statements of support and company blog posts on a page of its website.