The Facebook battle is similar to challenges percolating throughout the country from technology companies objecting to how the government seeks access to internet data in emails or social media accounts during criminal investigations.
The case has implications for the First Amendment rights of Facebook users and others who are politically active online.
The Constitution can only protect the targets of an investigation, according to the court filings, if they know their rights are under threat.
Prosecutors are trying to prevent Facebook from giving users a heads-up about search warrants connected to an investigation into potential felony charges. Prosecutors typically ask judges for nondisclosure orders when they are concerned that tipped-off targets will destroy evidence, flee or otherwise undermine an investigation.
The wording of the search warrants at the crux of the case seek "all contents of communications, identifying information and other records" and designate three accounts for a three-month period in each request, according to a Facebook court filing made public.
In April, a D.C. Superior Court judge denied Facebook's request to get rid of the gag order and directed the company to turn over the records covered by the search warrants to law enforcement.
Facebook appealed. The appeals court allowed the company to share some details of the sealed case to seek legal support for its cause from other businesses and organizations. Those organizations have since filed public legal briefs backing Facebook.
A spokesman for the U.S. attorney's office declined to comment on the sealed case scheduled for argument in September.
Nate Cardozo of the Electronic Frontier Foundation (EFF), which filed in support of Facebook's objections to the gag order, said the government has routinely overused nondisclosure orders to try to keep its surveillance activities secret.
When a criminal investigation, such as the one into Inauguration Day protesters, is widely covered, he said, "there is no need for it to remain secret."
In its public court filing, Facebook says it should be able to notify users in advance of the search because the public is already aware of the investigation.
"Neither the government's investigation nor its interest in Facebook user information was secret," the company said in its brief. The company also says it has preserved the records prosecutors are seeking.
The American Civil Liberties Union, EFF and the coalition of technology companies and the Reporters Committee for Freedom of the Press say the targeted Facebook users should have an opportunity to challenge the warrants in court when their rights to engage in anonymous political speech are at stake and when the government investigation is not a secret.
"The warrants' broad sweep would enable the government to review the targets' communications with third-parties, their political and social affiliations, their reading habits, and their views on a plethora of political, social, religious and personal issues," according to the ACLU brief filed by Arthur B. Spitzer.
Prosecutions of the Inauguration Day demonstrators are playing out in D.C. Superior Court with trials scheduled to begin later this year and run through 2018.