...but it's not:
Police: Ohio Riot Was Worse Than Expected
I understand the right to assembly is to be protected fiercely. I understand that sometimes protests can turn violent, and that merely the possibility of violence shouldn't be enough to preempt this right. But when the police are expecting widespread violence (aka. a riot is a certainty), shouldn't that be where we draw the line? What is the message here -- riots are okay, as long as they aren't bigger than the police anticipate??
On a tangential note: How exactly does one estimate the size of a riot? "Well Bob, we've got about 20 Neo-Nazis and about 25 inner city gang members. Our studies show us that about 60% of the Nazis and 50% of the gang members will actually light shit on fire. So, at 24.5 arsonists per hour, and a conversion rate of 9 arsonists per fire truck, it looks like 3 fire trucks should handle the fires from the rioting. Joe, can you present the looting data we had from the last riot, please?"