The reason why blacks can use the n-word and no other race can is because its our way of turning the negative output of the original word and slavery into a 'positive' word.
When another race uses the n-word it basically takes out the 'fun' of it because you remind us what happened in the past. The only other race that I've seen use the n-word is Hispanics and I don't mind.
I also don't mind other races using the n-word just don't go up to a random black person and instantly call them that . You can use the n-word just do it around your black friends (any friends) unless you are referring to the er version.
Plus its just a word, you're really going to get mad because you can't say a word when blacks have been through some rough **** and they are still going through it today.