SAN FRANCISCO — Apple Inc. is not known for collaborating on much. Indeed, its rivalries are part of Silicon Valley lore: Apple vs. IBM in the ’80s; vs. Microsoft in the ’90s; vs. Google in the ’00s; the list goes on. But this week marked unprecedented coordination among rivals behind the scenes as tech policy lawyers filed briefs on Apple's behalf, each biting off a different part of the argument that Apple should not have to build code to defeat its own encryption.

But don't for a minute think that love for Apple has anything to do with it.

The filings began to pour in Wednesday night and did not stop until the deadline Thursday evening. Each brief argues a different reason why a federal magistrate judge in California should vacate her order compelling Apple to build a so-called “back door” for the iPhone of Syed Rizwan Farook, one of two shooters who killed 14 people in the Dec. 2 San Bernardino attack. That back door would decrypt the iPhone's security and allow the FBI access to the shooter's information, but it could set a precedent that tech experts argue would put the digital privacy of users worldwide at risk to law enforcement, hackers, criminals and oppressive governments.

“Privacy is a fundamental right, and encryption is the technology that empowers that right electronically,” said Kenneth Carter, counsel for CloudFlare, a security company that filed a brief alongside 16 other companies.

The briefs acknowledge the FBI’s reasons for wanting access into the device and restate the tech industry’s commitment to helping law enforcement catch and fight criminals and terrorists when it is done within the law. But in this particular instance, the tech industry argues that the FBI and the federal court have overreached in a manner that could set several dangerous precedents.

One bloc of companies containing tech heavyweights Google, Facebook, Amazon, Microsoft, Yahoo, Mozilla and others argues that the FBI is misapplying the 227-year-old All Writs Act in a dangerous manner. “Should the U.S. government prevail in its arguments, the All Writs Act — a statute enacted 50 years before the telegraph — could be used to compel companies to write code to defeat their own security protocols,” Yahoo General Counsel Ron Bell said in a statement.

Another impromptu coalition containing the likes of Twitter, Square, Airbnb, CloudFlare and 13 others is advocating for the government to respect the security they have built in order to protect their users’ data privacy. “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,” the brief reads.

Meanwhile in Washington, numerous trade associations representing thousands of tech firms have also rallied to Apple’s side. ACT | The App Association, for example, dedicated its brief to explaining the unreasonable burden that would be placed on the thousands of independent developers it represents should they be put in the position that Apple now finds itself, compelled by the government to create new code it does not wish to write.

"It's untenable. The FBI is seeking the authority to have app companies do the their work for them,” said Jonathan Godfrey, vice president for public affairs at ACT | The App Association. “A startup would be forced to compromise its product to achieve the government's goals. This would be immensely burdensome."

It’s not so much that the tech industry is coming to Apple’s aid, but rather, Silicon Valley understands that it is in each company’s own self-interest to stand up to the FBI, many involved with the filings told the International Business Times.

"The tech industry is very competitive, and Washington can be a battleground where companies seek an advantage over their competitors. Schadenfreude is very prominent there,” said a source at a tech trade group. “And while many companies might like to see Apple take a hit, the underlying issues in this case are so important to the tech industry that they have to stand beside Apple on this."

Over a hectic and exciting two weeks, the general counsels at dozens of tech companies played “the jurisprudential equivalent of dating until you find the right brief,” according to one source whose company partook in a bloc filing.

By calling up old friends, rehashing previous joint briefs and partaking in group email threads among tech lawyers, counsels browsed through the various available briefs that were drafted and have now been filed, looking for the one that best fit their company, their culture and their mission.

For some companies, finding the right brief was all about the quality of the writing. “People are talking about this beyond Silicon Valley,” the source said. “We chose a brief that I think they could read on a Sunday afternoon and understand what it meant.”

Others went with the bloc that best addressed their company’s concerns. Security company AVG, for example, signed onto a brief that stressed the financial burden that building a back door for law enforcement would have on tech companies.

“Just think what that would do to a company like AVG. And we're not even a small player,” said Harvey Anderson, AVG’s chief legal officer. “There are actually economic consequences for the business and the shareholders.”

It’s rare that the fiercely competitive tech industry comes together in a joint effort such as this one, but it is not without precedent. Silicon Valley’s fight against lawmakers a few years ago on the SOPA and PIPA legislation was broader and sustained longer, but over the past two weeks, the tech industry has been quick to coordinate with friends and colleagues at other firms to show their strength in numbers. “You wouldn’t want to show a petition with one signature on it,” said Jennifer DeTrani, general counsel at Wickr, a secure, private messaging app. Wickr was among the companies that filed alongside Twitter.

Of course, not all filings have come in groups. AT&T and Intel each filed a brief separately. "Like all Americans, we were deeply saddened by the tragic events of San Bernardino," wrote David McAtee, AT&T general counsel. "In this case, however, the government seeks more than what can be supported under the law as it is written today. The solution is for Congress to pass new legislation that provides real clarity for citizens and companies alike."

The goal here is not to rescue Apple. Rather the mission is to ensure that the FBI does not put any other tech company in the spot Tim Cook and his crew now find themselves in. “It could’ve been any other company in this position, and our response would be the same,” said Justin Olsson, product counsel for AVG.