We're not talking about the late 60s Black Panthers here that were literally militarist protestors against the way blacks were getting treated by the cops and everyone else. (Not saying there aren't groups out there like this, but that isn't the BLM so far.) At any public gathering, there's always going to be an asshole or two looking for cover to do something stupid that will start a riot. (And to note: I'm simplifying the Black Panther movement. Read stuff elsewhere for real information.)
Just remember that evil comes to power when good people stand and turn a blind eye to what is going on. The question is... who's the bigger evil?
Oh, and never been flash banged before (unless some of the light shows at concerts I've been to count; flashpots a meter in front of your face are loud, bright, and you can feel the concussion rattle your bones... and you might get a few singed eyebrow hairs), but have been pepper sprayed. All that did was take a loud situation to a violent situation. if the guy that pepper sprayed me didn't shit his pants and run like cockroaches when you turn the light on, I'd have gone to jail from the beatdown that was coming.