Elon Musk’s X Corp. is suing the state of California over AB 587, a state bill requiring social media platforms to report to the state attorney general, semiannually, how they’re tackling moderation of certain categories of speech. The complaint alleges that the bill violates federal and state free speech laws because it “compels companies like X Corp. to engage in speech against their will,” as they’re forced to settle on definitions for “politically-charged” issues like hate speech or racism.

X Corp.’s complaint explains that it’s “difficult to reliably define” hate speech, misinformation, political interference, and other content categories. It adds that defining them is “often fraught with political bias” because there’s no accepted consensus within the public sphere about what the terms mean. X Corp. says that in defining those things, it’s being compelled to take a position on them.

The suit alleges that AB 587 is intended to make social media companies “‘eliminate’ certain constitutionally-protected content” that the state thinks is “problematic.” Governor Gavin Newsom’s office promoted it as a “nation-leading social media transparency” measure when he signed it into law in September last year. Laws specifying how social media companies handle moderation have been created in both Texas and Florida, and those laws are waiting for the Supreme Court to hear challenges to them.

Social media moderation isn’t a solved problem. X uses tools such as automated systems and community flagging for moderation and fact-checking. This week the company rolled out its Community Notes for videos, which allows “Top Writers” to submit context to potentially misleading videos, but could itself lead to misinformation. Reddit has recently drawn criticism after it started booting longtime moderators and replaced them with potentially less critical, inexperienced ones, while Bluesky’s own moderation manifesto acknowledged that its moderation approach could suppress fact-checking on the site.