Why do black lives matter?

Wildwood - Why do black lives matter? Some blacks are the ones making everything about being racist. They call each other the "N" word but as soon as a white person says it they are being racist, how does that make any sense? One black kid in Baltimore gets killed by a cop who was using standard textbook procedures to protect himself and some blacks were acting like zoo animals tearing up their own city. I think all lives matter.