New public court filings — in an otherwise sealed case — reveal a brewing First Amendment fight between Facebook and federal prosecutors over an order blocking the company from alerting users about search warrants for account information.

According to the limited information unsealed so far, Facebook received search warrants from the government for three account records over a three-month period. The warrants were accompanied by a nondisclosure order from a District of Columbia Superior Court judge barring Facebook from notifying users about the warrants before Facebook complied — an order the tech company is now challenging.

Most details about the case remain under seal, although one recent filing suggests that the warrants relate to the mass arrests in Washington, DC, during President Trump’s inauguration. BuzzFeed News obtained court papers filed on Friday by tech companies, civil liberties groups, and consumer advocacy organizations in support of Facebook’s challenge to the gag order.

“The Constitution can offer adequate protection only if the targets of seemingly overbroad warrants, such as those at issue here, know their rights are under threat,” lawyers for the American Civil Liberties Union and Public Citizen Litigation Group wrote in one of the briefs.

Facebook unsuccessfully challenged the gag order in Superior Court, and then took the case to the DC Court of Appeals. In a June 14 order, a three-judge panel of the DC Court of Appeals ruled that an unsealed notice about the case could be provided to any groups that Facebook or the government thought might want to weigh in.

Briefs in support of Facebook were due by June 30, and the government's response and any filings from outside groups in support of the government are due July 31. The court is scheduled to take up the case in September; the order did not specify a date.

According to the three-page public notice about the case from Facebook, the warrants relate to an investigation into potential felony charges, and “neither the government’s investigation nor its interest in Facebook user information was secret.”

The case raises two main issues, according to Facebook: First, whether the nondisclosure order violates the First Amendment when information about the underlying investigation is already public. Second, whether users whose accounts are at issue should have a right to contest the warrants when their First Amendment right to anonymous speech is at stake.

The scope of the warrants served on Facebook “is like a warrant telling officers to seize all the papers and photographs in someone’s home, so prosecutors can peruse them at leisure looking for evidence,” Arthur Spitzer, legal director of the American Civil Liberties Union of the District of Columbia, told BuzzFeed News in an email. “This violates the Fourth Amendment, which requires that warrants must ‘particularly describ[e] ... the things to be seized’ – a requirement that was designed to prohibit just such ‘general warrants.’”

Three briefs in support of Facebook were filed on Friday. One represented the views of eight tech companies – Microsoft, Google, Apple, Snap, Dropbox, Twitter, Yelp, and Avvo – along with the Reporters Committee for Freedom of the Press; another came from the American Civil Liberties Union and Public Citizen Litigation Group; and a third was filed on behalf of the Electronic Frontier Foundation, Access Now, Center for Democracy & Technology, and New America’s Open Technology Institute.

The brief filed by the Electronic Frontier Foundation and other digital rights groups includes a footnote that suggests the investigation relates to the mass arrests on Inauguration Day. More than 200 people are facing felony rioting and property destruction charges in DC Superior Court in connection with those arrests, and EFF’s brief noted that the timings of events referenced in Facebook’s case “coincide with the proceedings in the cases involving the January 20, 2017 Presidential Inauguration protestors.”

“The underlying warrants are apparently calculated to invade the right of Facebook’s users to speak and associate anonymously on a matter of public interest, and the First Amendment requires that the users be accorded notice and the opportunity to contest the warrants,” lawyers for EFF and the other digital rights groups argued in their brief.

A spokesman for the US Attorneys’ office declined to comment on whether the Jan. 20 cases relate to the Facebook warrants dispute, citing the fact that the felony rioting case are pending. Defendants in the rioting cases previously stated in court filings that prosecutors had sought information about their Facebook accounts. Several defense lawyers involved in the rioting cases declined to comment on the Facebook case.

A Facebook spokesperson said in a statement to BuzzFeed News that the company was "grateful to the companies and civil society organizations that are supporting us in arguing for people’s constitutional rights to learn about and challenge these search warrants.”