And that's just the neo-Nazis. /r/anarchism got quite nasty too, at one point, and God only knows what end of the spectrum /r/conspiracy are on.
And that's just the open extremist hate groups and subreddits that raid others on Reddit.
Just today I ran into a DailyKos thread from 2010 debating whether or not to ban reference to some blog on grounds that its text was indistinguishable to the already-banned Stormfront.
The internet is not nearly as censored a place once you get away from Facebook and CNN.