I live in Toronto, and I was pretty surprised today to hear about the violent protests in downtown. Apparently, a lot of the stores at the familiar Eaton Centre have been destroyed.
I was just watching on TV a live coverage of the events. A massive force of riot police were guarding the Queen's Park area, and it was pretty interesting to watch them holding back the crowd and occasionally doing "raids" to arrest so-called "leaders and troublemakers". Several such arrests were shown on the live coverage. It was very interesting how the police conducted such arrests: a "snatch squad" of officers in riot gear but wearing shorts (for running, apparently) would rush into the crowd and take down the target. The rest of the riot police would then advance in formation until they cover the "snatch squad" and guard them while the arrested person is hauled off.
There is also a squad of mounted police that would occasionally ride toward the crowd in order to disperse them. This really reminded me of ancient battles where you'd have a phalanx supported by cavalry.
I also couldn't help but notice that almost all news reports covering the protest would blame the violence on "a few" bad apples (namely, the Black Block). This really reminded me of the way CCTV reported on the Lhasa riots.