I was once a passenger in a car driven by a black friend. We got pulled over because his registration was expired.
I've dealt with a few cops and they are generally rude and brusque but this cop had an extra edge and unnecessary belligerence to his rudeness toward my friend who was polite and careful in all his movements. This fat white cop asked several times if my friend owned the car, the implication being that he thinks he stole it and he took extra time to run his license and he even called backup.
After it was over, my friend sort of shrugged and said that's driving while black.