1. Police and/or police agents dress up like protestors
2. Carefully coordinating with the police (and the corrupt/idiot new media), they target store windows and police cars.
3. The police just happen to be entirely absent from the scene, but luckily - by amazing coincidence - the news media just happens to have their cameras set up right where the action takes place. What are the odds?
Apparently pretty good because it happens over and over again.
Wash, rinse, repeat.
Every time there is a "peaceful demonstration turned violent" you can safely assume the odds are very good that the police played a role in it.
We have been reporting these operations in full technicolor detail since 1997 - nearly twenty years.