[trashface]

I believe dang has said there is an auto-flagger which will do that on posts that are getting too many controversial comments. Then a mod has to unflag it, if they want to do that.

Of course this does suggest a strategy for censoring topics that you don't want on the front page of HN: deploy a bot army to add inflammatory comments. I feel like I've seen effect on other posts (the tylenol post currently on the front page has that smell) but who knows.