Why do most black people..?

hate white people? where i live all the black and mexican people hate white people. :/ we go to the store and they glare at us even when i smile at them. and also i was playing black ops and there was a guy whose name was literally "kill whitey" and had an emblem he made of a white person with a bullet in his head. i don't just don't get it. can someone fill me in please?