Most in these crowds are white 20 year old plus girls. Probably from well to do families, have been to college and hate themselves for being white.
Easy to get upset when you are young and impressionable and witness a cop kneeling on neck of an unarmed man with handcuffs and 3 additional cops standing around the suspect, until life is snuffed off. I understand it was on suspicion of having passed a counterfeit $20 bill.
There are a lot of White punks but I see a helluva lot of blacks too.