I'm enjoying browsing a site called "Skeptics/Stack Exchange," not only because its members try to get a collective handle on interesting disputes of the day, but because they have a filtering system I've never seen used before. Although newcomers may register freely to use the site, they have to earn "reputation" points before they're allowed to take certain actions. Apparently anyone may take a stab at posting a question or answering a posted question, and may earn reputation points if the question or answer is admired. Anyone may also vote on whether a post was helpful, but only people who have accumulated minimum reputation points may vote to approve an answer, or to leave comments addressing whether the question is appropriately stated or the answer is convincing. (That's a distinction between "helpful" and "substantively appropriate" that I've never seen before.) There's an elaborate hierarchy of privileges. It takes a very large number of reputation points to gain the right to close questions.
The effect of linking a good reputation to the right to speak or to control the discussion is to eliminate most flame-throwing and many logical fallacies. The discussion on climate change managed to include both believers and skeptics in roughly even numbers, with the two sides actually attending somewhat to each others' arguments. That's a new one for me.