First Amendment Hurdle Looms for California’s Social Media Law

California’s new law requiring social media platforms like Meta Platforms Inc.'s Facebook and Twitter Inc. to disclose their content moderation policies is likely to face the same kind of constitutional challenge that derailed similar efforts by Texas and Florida to regulate the companies.

The law requires social media companies to post all of their internal content moderation policies and to submit semiannual reports detailing their moderation activities. The companies must state whether their policies define certain categories of listed content, including “hate speech or racism” and “extremism or radicalization"—and if so, how the terms are defined.

Unlike the Florida and ...