I don't see why black people rioting is relevant - Does it perpetuate stereotypes to bigots? Because white people can riot as well - Just look at austerity protests in Greece. The fact blacks riot is not proof that they're violent or that it's their fault - It's merely a reaction caused by controversial and racist police-citizen relationships
Whoever fights monsters should see to it that in the process he does not become a monster. And if you gaze long enough into an abyss, the abyss will gaze back into you