[Sherman Logan]

In the early twentieth century the group stirring up riots was usually some arm of the Communist Party.

Not entirely true. The Commmunists were only one of numerous leftish groups before WWI. They didn't become dominant till after they took over Russia.

Prior to WWI, most rioting, assassination, etc. were fomented or caused by anarchist groups or individuals.

There was, of course, some degree of solidarity between anarchists and commies.

[Vigilanteman]

Weather breaks up a riot faster than appeasement. It’s hard to riot when your teeth are chattering.

This is so true . . . which is why a water cannon with ice-cold water in low temperatures is such an effective tool.