Persistant Racism in WoW

The latest trend on my server is for overt rascism. There was a lot of abuse on General about black people and I reported using the 'language' facility but also raised a ticket as this seems to be getting out of hand. A GM told me that I should put people who do it on ignore and if they make enough comments Blizz will take some form of unspecified action. Last week a reported someone whose in game name was 'N*gg*r' (funny that I can't write this word on a forum but a player can have it as their name) and all that happened was a name change to 'Backtoblack'. The individual concern /w me to tell me that he knew nothing would happen and laugh. The question I have is why don't Blizz take this seriously? People know that they can make derogatory comments about black people or jews and that nothing will happen. Do Blizzard turn a blind eye because they are greedy and need the money, or because they tacitly approve of rascism. In the UK posting overtly rascist comments in a public forum (which I am told would include online games) is illegal and can lead to prosecution should the provider fail to take action. So Blizzard...what's your excuse?