According to some of the blacks I've spoken to on this topic, it's about ownership of the same racial epitaphs that they have been subjected to by other races and in particular, whites. They use it because they CAN. Also, it's a bit of a tongue-in-cheek joke used in the context of comeraderie. For any other race to use it in reference to them is the epitome of bad taste - and should get punished. Yes, it is a double standard.

I do the same thing with my Jewish best friend. But if anyone were to turn around and say the same things to either of us about our heritage (mine to a lesser degree than hers, of course), we wouldn't hesitate to blow the whistle. Women do that with other women but if men were to make some off color remark - even if it's the SAME remark - the reaction would be considerably different.

I think every subculture has this to a certain degree within their own context. It's how these groups deal with the stereotypes they have no choice but to live with - IMO.