California Governor Gavin Newsom has signed a law aimed at making web platforms monitor hate speech, extremism, harassment, and other objectionable behaviors. Newsom signed AB 587 after it passed the state legislature last month, despite concerns that the bill might violate First Amendment speech protections.

AB 587 requires social media companies to post their terms of service online, as well as submit a twice-yearly report to the state attorney general. The report must include details about whether the platform defines and moderates several categories of content, including “hate speech or racism,” “extremism or radicalization,” “disinformation or misinformation,” harassment, and “foreign political interference.” It must also offer details about automated content moderation, how many times people viewed content that was flagged for removal, and how the flagged content was handled. It’s one of several recent California plans to regulate social media, also including AB 2273, which is intended to tighten regulations for children’s social media use.

Newsom’s office billed the law as a “first-of-its-kind social media transparency measure” aimed at fighting extremism. In a statement, he said that “California will not stand by as social media is weaponized to spread hate and disinformation that threaten our communities and foundational values as a country.” But the transparency measures are similar to those of several other proposals, including parts of two currently blocked laws in Texas and Florida. (Ironically, the other parts of these bills are aimed at preventing companies from removing conservative content that frequently runs afoul of hate speech and disinformation rules.)

Courts haven’t necessarily concluded that the First Amendment blocks social media transparency rules. But the rules still raise red flags. Depending on how they’re defined, they could require companies to disclose unpublished rules that help bad actors game the system. And the bill singles out specific categories of “awful but lawful” content — like racism and misinformation — that’s harmful but often constitutionally protected, potentially putting a thumb on the speech scale.

It’s not yet clear whether AB 587 will be challenged the way Texas and Florida’s rules were. NetChoice, one of the trade associations that’s led the fight against those laws, issued a statement opposing Newsom’s decision. But it didn’t immediately respond to questions about whether it would pursue legal action.