Yikes, pg is not gonna be happy. Honestly I feel like the only option is to just stop accepting new members at a certain point, because above a certain tolerance it stops being a community and becomes a city. CIP: I'm in a rural town for a couple days and everytime I walk outside everyone I pass says "Hi" or "Good Afternoon," the first time that happened I was kinda surprised I tried to figure out if I knew that pers…
At the very least, there needs to be a rudimentary troll block. I so tire of HN comment threads littered with discarded opinions from one-off accounts. Make accounts read-only for the first two-weeks and make sure they're actually being logged into and aren't being harvested.
Really, one-off accounts seem to be the HN version of anonymous posting. Which suggests to me that it may be more beneficial, perhaps, to simply allow anonymous posting with some caveats (any user can choose to block all anonymous posts, anonymous posters couldn't be upvoted or downvoted, it automatically triggers some kind of alert to the mods to watch the post, and maybe it even costs you karma to use the feature.)
I also keep considering that some kind of API which allows users to choose to block other users might be an effective form of self-policing, but that would also kind of by definition stifle and fragment conversation.