Pittsburgh Hosts G20, Police
While no protests were “legally” allowed, and despite police activity designed to intimidate potential demonstrations, some discontents found their way to protest the G20 meeting hosted in downtown Pittsburgh.
http://www.cnn.com/video/#/video/us/2009/09/24/tsr.todd.g20.tear.gas.cnn
CNN got some good video of the police using chemical weapons on anyone who happened to be in the wrong place at the wrong time.