A U.S. district court judge ordered Meta on Friday not to provide the Department of Homeland Security with the personal information of Instagram users accused of releasing personal details about a border patrol agent.

DHS sent subpoenas to Meta earlier this month, seeking the names, email addresses and phone numbers associated with Instagram accounts that posted the name of the agent, saying the requests were related to “Officer Safety / Doxing.”

Homeland Security Secretary Kristi Noem has warned that the agency would take action against “those who dox ICE agents to the fullest extent of the law,” citing cases where people have posted officers’ names online.

Why it matters: The subpoenas sent on Sept. 3 to Meta are the first known instance of DHS attempting to uncover the identities of people posting immigration enforcement officers’ information on Instagram.

Activists have been posting the names and photos of officers involved in immigration enforcement operations online in efforts to publicly shame officers. DHS officials argue masks protect officers’ safety, while critics say it prevents accountability for law enforcement officers.

U.S. Magistrate Judge Thomas Hixson for the U.S. District Court of the Northern District of California issued an order on Friday directing Meta “not to produce the requested information without further order of the Court” until the court decides on the subpoena’s legality.

“I’ll be able to sleep tonight without worrying that government agents are going to come pounding at my door simply for exercising my First Amendment rights,” the owner behind the Instagram account @LBProtest, said in a statement sent to POLITICO.

In an affidavit filed under J. Doe on Thursday, they said the account was anonymous to keep the Instagram posts separate from their personal and professional life.

What happened: Both the Civil Liberties Defense Center and the American Civil Liberties Union filed motions on Thursday to prevent Meta from disclosing information about activists’ Instagram accounts to the Department of Homeland Security.

The ACLU of Northern California filed on behalf of the Instagram account @LBProtest, while the Civil Liberties Defense Center filed on behalf of Stop ICE.

“I believe the government is targeting me because it disagrees with the content of the speech that I have posted and reposted online. I believe that my anonymity is the only thing standing between me and unfair and unjust persecution by the government of the United States,” the @LBProtest account owner said in an affidavit.

The judge’s order Friday only applies to the @LBProtest account, and the subpoena sent to Stop ICE is under review by U.S. Magistrate Judge Kandis A. Westmore.

The defense: The filings argue that DHS’s requests violate First Amendment protections for anonymous political speech, and also note that it is legal to record law enforcement agents and publish their identities.

“The First Amendment protects the right to record government agents in public, publish their identifying information, and criticize their conduct — including through videos and memes posted online,” Jacob Snow, a senior staff attorney for ACLU of Northern California, told POLITICO in a statement.

“People must be able to speak out anonymously, especially when the government is actively targeting people for their speech.”

A Meta spokesperson declined to comment on the subpoenas but pointed to the company’s Transparency Center, which details how the tech giant responds to government requests. It notes that Meta can push back on requests “if we determine that a government request is not consistent with applicable law or our policies.”

DHS did not respond to a request for comment.

“The subpoena is a retaliatory attempt by DHS and immigration enforcement designed to target those exercising their First Amendment right,” Stop ICE said in a post on Instagram.