Who benefits from Section 230, the federal law that shields online platforms from liability for content posted by users? According to commentators and politicians, Section 230 helps only large tech companies. But the biggest beneficiaries of Section 230 are internet users, not internet companies. Before Congress undermines Section 230, it must understand how users rely on it — and how the internet would change without it.

Section 230 — originally enacted by the Communications Decency Act and also referred to as C.D.A. 230 — says that internet platforms will not be held liable in court for things that their users say online. It has some exceptions — notably, it does nothing to shield platforms from liability under federal criminal law — but at its core, the law is a simple, common-sense policy: If I go online and post something illegal, I should be the one held responsible, not the message board where I posted it.

Without Section 230, the internet would be a more confined place, one with fewer spaces where we can all gather, socialize and share ideas. Social media platforms like Twitter, Facebook and Reddit wouldn’t exist — at least in their current form — and neither would knowledge-sharing sites like Wikipedia, the Internet Archive and Stack Exchange. If these companies were held liable for everything their users posted, the risk of litigation would make running them extremely dangerous.

If lawmakers weakened Section 230, they wouldn’t just be threatening those spaces — they would risk kicking some people completely off the internet. Without Section 230, platforms would effectively have to determine the risk of a user before that user would ever be allowed to speak. History shows that when platforms clamp down on their users’ speech, the people most excluded are the ones most excluded from other aspects of public life, too. Facebook’s “real names” policy kicked a Native American, Shane Creepingbear (his real name), off the platform. Under their policies on violence, both Twitter and YouTube suspended the accounts of Egyptian journalist Wael Abbas, who’d used the platforms to report on police brutality. Again and again, marginalized communities bear the brunt of heavy-handed censorship by platforms.