X, the company formerly known as Twitter, is suing California over a state law passed last year that lawmakers say aims to make social media platforms more transparent.

The law, Assembly Bill 587, requires social media companies to disclose their policies, including what content users are allowed to post on their platforms and how it responds when they violate the platform’s rules. The companies are required to submit this information to the California attorney general by January 2024. The attorney general’s office would then make those reports public online.

In the lawsuit, filed in a federal court in Sacramento on Friday, X alleges the law violates the 1st Amendment’s free speech protections and would pressure social media companies to moderate “constitutionally-protected” speech the state finds “undesirable or harmful.”

“The legislative record is crystal clear that one of the main purposes of AB 587 — if not the main purpose — is to pressure social media companies to eliminate or minimize content that the government has deemed objectionable,” the lawsuit states.

The lawsuit highlights the ongoing challenges lawmakers face as they try to make social media platforms safer amid concerns about hate speech, child sexual abuse and misinformation. It also comes after X started to rethink how it enforces its own policies since Elon Musk, who has described himself as a “free speech absolutist,” took over the social media platform last year. The company says it restricts the reach of tweets that may violate its rules — which prohibit harassment, hateful conduct and other potentially harmful speech — but stopped publishing formal biannual reports about how it enforces those policies.

Content moderation, the practice of reviewing users’ posts and deleting those that violate standards, has been a political issue. While Democrats say social media platforms haven’t done enough to moderate content, allowing harmful messages to spread, Republicans have accused these companies of censoring speech. NetChoice, whose members include X, also sued the state last year to block a children’s online safety law from taking effect, alleging it would lead to removal of lawful speech.

Assemblymember Jesse Gabriel (D-Encino), who wrote the bill that X is challenging, said in an interview he’s a “believer in free speech” and when lawmakers drafted the legislation they were mindful of constitutional concerns.

The law, he said, doesn’t require companies to have content moderation policies and is purely about transparency.

“I’m very hopeful and optimistic that this lawsuit is not going to succeed and that the courts are ultimately going to find this law is constitutional,” he said. “We put a lot of thought into that.”

The attorney general’s office didn’t immediately respond to a request for comment.

Social media platforms such as X already publicize what content users are and aren’t allowed to post. But X says in the lawsuit it has a problem with providing the attorney general’s office with more detailed information about how it’s moderated content on “controversial and politically-charged issues.”

The lawsuit also alleges that it would burden social media companies with keeping track of its daily content moderation decisions. A social media company that violates the new law would also be liable for a penalty of up to $15,000 per violation per day.

Since Musk’s takeover of Twitter, the company has lost roughly 80% of its employees and struggled to attract more ad dollars.