Eh, those idiot leftards have been threatening to riot off and on ever since Bush II got elected.
Agent provocateurs attempt to entrap their victims so the police have something to do.
The people trying to arrange riots are rabble rousers and trouble makers trying to trick the victims or the police into doing something dumb so they can claim police brutality, etc.
By the way, I think Soros has read this:
Four Minute Men - Wikipedia, the free encyclopedia
If you read and post in a large number of forums and news groups, you will find "four minute men" in many of them. I don't know if they are volunteers or paid agents.