Anonymity has long been hailed as one of the founding philosophies of the Internet, a critical bulwark protecting our privacy. But that view no longer holds. In all but the most extreme scenarios—everywhere outside of repressive governments—anonymity damages online communities. Letting people remain anonymous while engaging in fundamentally public behavior encourages them to behave badly. Indeed, we shouldn’t stop at comments. Web sites should move toward requiring people to reveal their real names when engaging in all online behavior that’s understood to be public—when you’re posting a restaurant review or when you’re voting up a story on Reddit, say. In almost all cases, the Web would be much better off if everyone told the world who they really are.