AnimeMute wrote:black people do call other black people the N word
Yes, some do. In my experience, it usually isn't used in an insulting context the way it would be when used by a person of another race as a slur, it would be used in the same way some people call each other "dude."
Being part of a group grants a person certain rights and previleges within the group. There are some things that are considered acceptable for members of a group to say to or about other members of a group that would be viewed as an insult if an "outsider" did it.
If you needed to take a shower, and a random stranger on the street came up to you and said, "Man, you stink" you'd probably be angry. If a family member said the same thing, you might be annoyed by their lack of tact, but you'd take it under advisement.
To use another example, if you and your friends were walking down the street talking about anime, and another Evil Random Stranger overheard and said, "You anime nerds are stupid dorks," you'd probably be annoyed. On the other hand, anime fans talk about themselves as a group being dorks and geeks all the time, and very rarely does anybody stand up and say, "Hey, speak for yourself, you jerk!"
That's just the way it is. But this is very off-topic.