The EJMR situation appears to be pretty horrific, and also pretty typical. As it's a specific culture (not a general social site like FB or, well, HN) I'm particularly glad it's being called out and investigated.
Go anywhere sufficiently anonymous and with laissez-faire moderation and you see similar things. Spend enough time in these places and you get the feeling that pluralistic western society is held only by a thread. (Though I hope it's just probably just a symptom of too much internet uaage)