Flag? Probably not often, and that is because controversy is not a bad thing; those discussions don't need to be flagged. That is the point I am making here,

Flag? Probably not often, and that is because controversy is not a bad thing; those discussions don't need to be flagged. That is the point I am making here, HN handles controversy very well, except certain types of topics generate flamewar, not mere controversy. Those get smacked down. Downvoted? Probably more often than you would guess; many people downvote for disagreement just as they upvote for agreement. As an example: Go (language) is a popular but quite controversial topic here. It is pretty easy to get downvoted in discussions on the merits of the language, but those discussions don't get flagged off the site and flamewars are rare (if present at all).