Update #2: A second coalition of tech companies including Google, Microsoft Facebook, Snapchat, Mozilla, and Dropbox have also filed a joint brief this evening in support of Apple. These companies also argue that the All Writs Act does not give the government legal basis for forcing Apple to unlock the gunman’s iPhone (via Reuters). Google detailed its reasoning in a blog post:

Today, Google joined a variety of technology companies to file an amicus brief in US federal court. Together, we are voicing concern about the use of a broad statute from the 18th century, the All Writs Act, to require companies to re-engineer important security features that protect people and their data.

Update: 5 families of the San Bernardino victims have filed an amicus brief with the court asking for Apple to unlock the iPhone in question. More below.

On a new webpage dedicated to highlighting companies and organizations supporting it in its fight against the FBI, Apple today has shared a joint amicus brief from a variety of tech companies that has been filed with the court. Twitter, Airbnb, LinkedIn, Square, Reddit, and many others have signed the brief expressing support for Apple.

It was reported earlier today that over 40 companies are expected to file in support for Apple, and this joint filing makes up for a good portion of those. In the filing, 16 companies say that the FBI’s claim that Apple must unlock the iPhone of one of the San Bernardino gunmen under the All Writs Act carries no legal basis.

Like the filing from the ACLU stated yesterday, the companies today reiterate that it is not Apple’s duty, as a private company, to create software to break into its own devices. The 26 page brief, which can be read in full here, is cosigned by all 16 companies and argues that Apple should not be forced to unlock the iPhone:

“The government’s efforts in this case—to force a private company to affirmatively develop software that does not currently exist in order to break its own security systems—would erode the privacy and protection of user data, and transparency as to how such data may be used or shared.

The government’s demand here, at its core, is unbound by any legal limits. It would set a dangerous precedent, in which the government could sidestep established legal procedures authorized by thorough, nuanced statutes to obtain users’ data in ways not contemplated by lawmakers.”

The full list of companies who have signed this filing is: Airbnb, Atlassian, Automattic, CloudFlare, eBay, GitHub, Kickstarter, LinkedIn, Mapbox, Medium, Meetup, Reddit, Square, Squarespace, Twilio, Twitter and Wickr.

Furthermore, AT&T today has shared its own amicus brief submitted to the court in support of Apple. While in the past AT&T has wavered on whether companies should be forced to retrieve user data, it sides with Apple in this case and says the case should be decided by Congress:

Today, AT&T filed a “friend of the court” brief with the magistrate judge for the U.S. District Court for the Central District of California, urging the court to vacate its order requiring Apple to take some fairly extraordinary steps to assist the FBI in unlocking the iPhone used by one of the perpetrators of the San Bernardino shootings.

Technology has changed dramatically since Congress last addressed these issues in 1994.  Then, Congress focused on what telecommunications carriers like AT&T may be required to do to assist law enforcement and national security officials.  Now, the government seeks data stored by many other types of companies, from device manufacturers to social media, search, and applications companies, among others.  But our laws have not kept pace with technology.

The solution is for Congress to pass new legislation that provides real clarity for citizens and companies alike.

Yesterday, Apple received support from the ACLU, Wickr, Access Now, and a United Nations free speech group. Many more are expected to support Apple, as well.

Furthermore, 5 families of the San Bernardino victims have filed an amicus brief with the court asking for Apple to unlock the iPhone in question. In the filing, obtained by Re/code, the families argued that unlocking the device could answer questions such as if there’s another attack coming and if anyone else was involved in the original attack. The families say that the court should focus on this specific case now, and push the larger debate about user privacy versus national security to “another day and another form.”

“No one knows with certainty that unique data resides on the phone,” wrote attorney Stephen G. Larson, adding, “It may, if nothing else, give some measure of closure to the survivors and families of loved ones who have suffered every day since this terrible crime. [The families] are eager that no stone be left unturned in investigating this horrible act.”

“Recovery of information from that iPhone in question may not lead to anything new,” another wrote. “But, what if there is evidence pointing to a third shooter? What if it leads to an unknown terrorist cell? What if others are attacked and you did nothing to prevent it?”