Elon Musk’s X Corp. sued California to undo the state’s law aimed at exposing sources of hate speech and disinformation by requiring social media companies to explain how they moderate their content.

X, which operates the social network that used to be known as Twitter, argued in a lawsuit filed Friday in federal court in Sacramento that the law interferes with its editorial judgments that are protected as free speech under the Constitution.

California Governor Gavin Newsom said when he signed AB 587 last year that it was designed to protect the public by demanding companies reveal their policies on hate speech, disinformation, harassment and extremism on their platforms, and report data on their enforcement of the policies.

But the law’s true intent is “to pressure social media platforms to ‘eliminate’ certain constitutionally protected content viewed by the state as problematic,” according to the complaint.

When Musk acquired the social media company for $44 billion last year, he vowed it would be free of censorship and he reinstated formerly banned users while firing content moderators. The self-styled “free speech absolutist” hired NBCUniversal ad executive Linda Yaccarino as chief executive officer in May to help repair partnerships in the media industry and lure back advertisers.

Researchers have said that during Musk’s tenure, the platform has seen a spike in harmful content due to policy changes in content moderation.

This month Musk blamed the Anti-Defamation League for a slump in US advertising revenue on X. He accused the nonprofit of trying to kill the platform with false accusations that he and the company are anti-Semitic. 

In July, X sued the Center for Countering Digital Hate, accusing the nonprofit of falsely describing X as being “overwhelmed with harmful content.”

An earlier legal fight over California’s content moderation law suggests Musk may face a tough road. Last month, a federal judge dismissed a challenge to AB 587 by groups including the National Religious Broadcasters, ruling that they failed to allege an actual danger from the measure. The judge gave the groups a chance to revise the complaint.

California Attorney General Rob Bonta’s office declined to comment.