> The bottom line is that no active moderation system, no matter how many users are empowered to rate each other and each other's comments, can preserve community in the face of the multiple identity syndrome inherent to online forums.
This isn't true. Depending on what you want to design against you can use both social signals (downvotes) and a web-of-trust for singular identity and another one for dealing with spam / trolling and you can keep anonymity, you can keep good content, you might get some bubbling at the extremes, but you know what? I don't want to listen to Alex Jones idiots anyway, and with the proper graph analysis techniques you can filter out the Alex Joneses while keeping in the Bill Kristols.
Also, a poor mans web-of-trust is the invite only ban both model. If you invite me in, and I get banned you get banned too and anyone else you invited has their remaining invites revoked.
We have the science to tackle shitty online behaviour. The problem is that it destroys metrics for social networks. There are not 335 million people using Twitter a month, even if there are 335 million "active accounts".