no need to take such measures. just disallow folks from submitting articles and voting under a certain karma level. they need to earn the right to participate b

no need to take such measures. just disallow folks from submitting articles and voting under a certain karma level. they need to earn the right to participate based on making worthwhile comments. We can automatically remove any user with a karma level too low (-20?). So new users have a choice: make good comments and participate in the discussion, or start get banned relatively quickly for making digg/reddit level comments.