I'm a little surprised no one's tried reviving newsgroups for discussions. Decentralized, not privacy-invading, can be rendered by a large variety of front-ends. Somewhat censorship resistant. There would be a huge potential spam problem, but that can be controlled by filters and moderators.
Maybe Usenet would be more of a headache than it's worth, but it seems perfect for what you're describing.
Maybe Usenet would be more of a headache than it's worth, but it seems perfect for what you're describing.