Explaining the Ferguson Riots

There's only one explanation of why the reaction to a slightly-dubious grand-jury decision was to loot stores and burn down neighborhoods:

This story is emblematic of something I've noticed seems increasingly common in the 21st century---political movements that appear exceedingly stupid.

On the other hand, it appears that this was stupidity imported from outside Ferguson.

Come to think of it, this might explain why the prosecutors waited until nightfall to announce the decision instead of announcing it in narrow daylight. (In November, daylight isn't broad.)