The Elon Musk-run platform alleges the Stop Hiding Hate Act “impermissibly interferes with the First Amendment-protected editorial judgments” of companies like X to decide how to moderate content. Platforms could face fines unless they disclose what X calls “highly sensitive and controversial speech,” which it says the state may not like. The Ninth Circuit Court of Appeals already blocked parts of a similar California law on First Amendment grounds, following a separate X challenge.