pg's quoted comment http://news.ycombinator.com/item?id=1833255
I've noticed that if you reply to a mean-spirited comment with a straightforward and dispassionate counter-argument, completely ignoring its rudeness and tone, you get massive upvotes. Transcending meanness also feels really clean; it is neutralized.
By framing the meanness, the site's collegiality is not undermined, but demonstrated.