Whenever I hear that unrest in a community is the result of "outside agitators," I am reminded of a story about Da Nang in Viet Nam in 1946. Two organizers from the Indochinese Communist Party were sent to organize the population there and sparked a series of riots in which the population took the stores of rice being guarded by the government. The French blamed the communists, of course.
Now first, one should be intrigued by the competence of an organization that can spark riots by sending two people. They must have been really good.
But then one should check out the backstory. What was going on that led the population to riot? We find that the French colonials were selling rice to the Occupation forces in Japan. They had bought up all of the rice, leaving nothing for the starving population. In one of the usual colonial acts of insensitivity, the French had the rice guarded by the Japanese prisoners of war who had been captured in the region. The population of Da Nang was starving, and there should be some doubt that the Indochinese Communist Party was, independent of the legitimate anger of the local citizenry, so good as to bring about a demonstration, let alone rioting.
But now we find that outside agitators have come to Ferguson. We are already finding out that the spark was the killing of Michael Brown, but the poor and black population of Ferguson had a number of long-standing issues with their local police, whether or not the cops were dressed for battle in Iraq, and that much of the municipal government's budget was raised from petty harassment of the African American citizenry. Remember that Michael Brown was first stopped for jaywalking, one of those lovely little discretionary citations that raises money for the local government.