Requiring internet users to provide their ID or other proof of their age could block people from accessing lawful speech if they don’t have the right form of ID, the brief argues. And requiring users to identify themselves infringes on people’s right to be anonymous online.

Utah cannot stifle young people’s First Amendment rights to use social media to speak about politics, create art, discuss religion, or to hear from other users discussing those topics, EFF argued in a brief filed this week.