The company that operates the social network that used to be known as Twitter argues the measure, AB 587, interferes with its editorial judgments protected as free speech under the Constitution.

When California Governor Gavin Newsom signed the bill last year, he said it was designed to protect the public by requiring social media companies to 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. 

Advertisers have fled the platform since Musk bought it for $44 billion last year and started making changes, including reinstating formerly banned users and firing content moderators. Musk changed the name to X from Twitter.

During his tenure, the platform has seen a spike in harmful content due to policy changes in content moderation, according to researchers. The self-styled “free-speech absolutist” hired an executive charged with repairing partnerships in the media industry and luring back advertisers.

California Attorney General Rob Bonta’s office didn’t immediately respond to a request for comment.

Last month, a federal judge in California dismissed a previous challenge to the law brought by groups including the National Religious Broadcasters, ruing that the plaintiffs failed to allege an actual danger from the AB 587. The judge gave the groups a chance to revise the complaint.