It depends. Sometimes I see comments that I don't understand are downvoted - I upvote these and sometimes comment. But most downvoted comments are downvoted fo

It depends. Sometimes I see comments that I don't understand are downvoted - I upvote these and sometimes comment. But most downvoted comments are downvoted for an obvious reason: they're snarky, personal, ad-hominen attacks, trolls or just plain wrong. It wouldn't add anything to the discussion to comment. Here's an example of a snarky comment which deservedly got downvoted for obvius reasons: http://news.ycombinator.com/item?id=2038245 http://news.ycombinator.com/item?id=2038245 (it's mine - and I apologise...)