X is suing a group of major advertisers over accusations that they held an “illegal boycott” against the platform formerly known as Twitter. In a lawsuit filed on Tuesday, X claims Unilever, Mars, CVS, Ørsted, and dozens of other brands conspired to “collectively withhold billions of dollars in advertising revenue” through a World Federation of Advertisers (WFA) industry initiative.

To join the WFA’s initiative, called the Global Alliance for Responsible Media (GARM), companies must agree to withhold advertising from social platforms that aren’t compliant with the organization’s safety standards. X alleges GARM “organized an advertiser boycott of Twitter” to coerce the company into following the initiative’s safety standards. The lawsuit is being filed despite X announcing that it was “excited” to rejoin GARM last month.

“The evidence and facts are on our side,” X CEO Linda Yaccarino said in a video posted to X. “They conspired to boycott X, which threatens our ability to thrive in the future. That puts your global Town Square — the one place that you can express yourself freely and openly — at long-term risk.”

A separate post from Elon Musk said he “strongly encourage[s] any company who has been systematically boycotted by advertisers to file a lawsuit,” as there could also be “criminal liability” under the Racketeer Influenced and Corrupt Organizations (RICO) Act — a law that aims to crack down on organized crimes.

X’s lawsuit, which you can read in full at the bottom of this story, cites a July 10th report about the WFA from the House Judiciary Committee, which said the WFA and GARM’s “collusive conduct to demonetize disfavored content” was “alarming.” Earlier this month, House Judiciary Chair Jim Jordan (R-OH) sent letters to 40 companies involved with GARM to ask why the advertisers “boycotted” right-wing outlets like The Joe Rogan Experience, The Daily Wire, Breitbart, or Fox News. Musk already threatened to sue the advertisers partaking in the alleged boycott.

It’s not clear how well X’s lawsuit will fare in court because, as pointed out by Techdirt, the ability to choose where to advertise is protected under the First Amendment. The ad tech watchdog group Check My Ads similarly states that advertisers have the right “to not send money to a platform that promotes hate and conspiracies.”

X is asking the court to declare the advertisers’ actions illegal and award the company damages that will be determined at trial. This lawsuit is the latest in a string of largely unsuccessful legal actions taken by Musk. While he dropped his lawsuit against OpenAI and its cofounders in June, he sued them again on Monday over claims they “manipulated” Musk into cofounding the nonprofit to build safe and transparent AI.