Very true. I think this was a very pre-emptive warning about humanity:

"Progress, far from consisting in change, depends on retentiveness. When change is absolute there remains no being to improve and no direction is set for possible improvement: and when experience is not retained, as among savages, infancy is perpetual. Those who cannot remember the past are condemned to repeat it." - George Santayana

I worry less about the rioters than I do about the general population calling for lynching and murder.