A site where everybody is invited to submit content anonymously but it's heavily censored & moderated becomes a mouthpiece for the moderators. It's basically Yelp, or the Op-Ed section of a newspaper.
Interesting comparisons, but I would have to say those places still have a sense of identity, even if it's one cooked up 30 seconds ago with a 10minuteemail address.
I'm more curious about a site with the "enforced" lack of identity present on those imageboards, except with the ruleset of Twitter or Facebook.