That’s true. They actually have to have bodies out there in order for them to foment a riot.
Weather aside, the scenario I see goes like this -
you have a bunch of disgruntled “gimmes” hanging out with no focus, and along comes Mister Union Thug Organizer
and gives them some “direction”. After the first window breaks and nothing is done about it, bar the doors.
Another scenario is at the GOP convention were the useful idiots have been bussed in to be used as human shields by the anarchists & union goons, who will herd them in front of & around buses carrying convention goers & all of a sudden a molotov cocktail gets thrown to the cheers of the useful idiots who have their heads crammed full of socialist sophomoric slogans. Then the fight is on.