This looks like a feature in web archive: it already keeps snapshots of web pages, so it could add a comments section. It can dodge the moderation problem entir

This looks like a feature in web archive: it already keeps snapshots of web pages, so it could add a comments section. It can dodge the moderation problem entirely by not hosting the comments: instead it would render comments from rss sources provided by the user agent, and the user will be responsible for discovering those sources. Personal rss sources could be pinned to domain names, and there need to be some aggregator that combine thousands of sources - those will be moderators of their "herd". Users would advertise their rss comments just like they advertise their twitter pages. There won't be a global view on all comments on a specific page: everyone will see something different, and that's good. All this hinges on the will of the admins of web archive to implement a comments renderer. Another thought is that such a comments platform already exists: bitcoin. Anyone can attach a message to a hash associated with a url (for a fee). It's gonna be awfully slow, though. And since it's global, any popular url will be buried under mountains of trash, including stuff that will make govs shut down bitcoin completely.