Sorry, didn't mean to imply that all the sites I referenced employ all of those techniques, just a subset of them. I was mostly thinking of Stack Overflow when

Sorry, didn't mean to imply that all the sites I referenced employ all of those techniques, just a subset of them. I was mostly thinking of Stack Overflow when I talked about community-appointed moderators, though I think with Reddit you could argue that users do have some limited influence over who their moderators are. If a large enough majority doesn't like the mods of a particular subreddit they can fork the community with a new subreddit and move everyone there. Not an ideal solution I'll admit, but I have seen it work.