My brother (former White supremacy) is 16 and still pretty naive in regards to how things such as this could be interpreted. I think its clear that no harm was intended and its probably a good thing that he was made aware of potential situations like this. I guess a lot of the more "charged posts" were deleted but I thought it would be beneficial for the members of the forum to understand the slip up.
I did however think it was quite humerous/ entertaining how upset a couple people got to include making death threats over an internet forum only to perpetuate the very stereotype they aim to prevent. I myself am a very staunch enemy of racism/ harmful over-generalizations and would offer the advice to handle a situation such as this with more tact.