Updated

Twitter has filed a lawsuit against the U.S government over an attempt to reveal the identities of the users behind the @ALT_USCIS account, which has been critical of President Trump’s administration.

A “rogue” government account, @ALT_USCIS describes its goal as “immigration resistance” and is now at the center of the row between Twitter and two government agencies - the Department of Homeland Security and U.S. Customs and Border Protection.

Twitter wants to prevent the agencies from “unlawfully abusing a limited-purpose investigatory tool to try to unmask the real identity of one or more persons who have been using Twitter’s social media platform,” according to the lawsuit. The users have harnessed @ALT_USCIS “to express public criticism of the Department and the current Administration,” it adds.

TRUMP SAYS HIS TWITTER POWER IS WHY KAEPERNICK IS A FREE AGENT

@ALT_USCIS is one of a number of so-called “alternative agency” accounts set up on the social media site following Trump’s inauguration, Twitter explains. These accounts provide a platform for purported current or former employees of federal agencies, without revealing their identities.

“Like other accounts of this sort, @ALT_USCIS claims to be run by one or more current government employees—in this case, employees of the United States Citizenship and Immigration Services,” Twitter says, in its suit. “And as with other such accounts, the person or persons who established and speak through @ALT_USCIS have identified themselves only by means of this pseudonymous account name.”

On March 14 Twitter received a CBP summons “demanding that Twitter provide them records that would unmask, or likely lead to unmasking, the identity of the person(s) responsible for the @ALT_USCIS account,” according to the suit, which describes the summons as unlawful. “Permitting CBP to pierce the pseudonym of the @ALT_USCIS account would have a grave chilling effect on the speech of that account in particular and on the many other ‘alternative agency’ accounts that have been created to voice dissent to government policies,” it added.

MCDONALD'S TWITTER ACCOUNT HACKED, BLASTS TRUMP

The account has racked up over 35,000 followers since it was set up in January 2017. In its description, @ALT_USCIS says that it does not express the views of DHS or the United States Citizenship and Immigration Services (USCIS).

The @ALT_USCIS account tweeted part of Twitter’s lawsuit Thursday.

The ACLU told Fox News that it is representing the user in the @ALT_USCIS case. "The right to anonymously speak out against the government is clearly protected by the First Amendment," said ACLU attorney Nathan Freed, in a statement emailed to Fox News. "We are pleased to see Twitter standing up for its users’ rights, and the ACLU will soon be filing documents in court on behalf of this user."

The ACLU’s national Twitter account also tweeted its support for the social media site Thursday.

FOR THE LATEST TECH FEATURES FOLLOW FOX NEWS TECH ON FACEBOOK

Twitter declined to comment on its legal action when contacted by Fox News. The DHS and CBP have not yet responded to a request for comment on this story.

Twitter’s lawsuit was filed Thursday in the U.S. District Court Northern District of California.

Follow James Rogers on Twitter @jamesjrogers