People create throwaway accounts all the time. Allow people a limited number of posts per day to anonymize their screen name. I think you'll get much more candor on some topics. And with this you can better sort comments and stories since HN will still have access to karma and other signals. And perhaps on an anon post, we could see an anonymized version of their karma (what range their karma is in, say 0-49, 50-399, 400-999, 1000+). This might allow us to take someone's anon comment more seriously.