The vandals dressed in black are not to be confused with the peaceful protesters who attempted to let the leaders of the G-20 know how they felt about the never-ending war in Afghanistan, the same austerity measures they are always recommending for us but not for banks or corporations, Harper's stand on the maternal health care issue and a myriad of other issues. None of which will now get a hearing because a bunch of thugs claiming to be anarchists marched up and down Toronto streets breaking things for reasons that make little sense to me.
The idea is usually stated these acts are undertaken so as to show the face of the oppressor - the police state. Thing is, it doesn't work. Most people, when they see this stuff get angry and want to see the protests stopped. That includes legitimate ones along with the idiocy and violence.
And that's the thing. The only thing that works is non-violence. Civil disobedience is fine but it has to be civil. If you want to show the face of an oppressive state try a non-violent protest. If the police attack that then you'll achieve your goal of unmasking the state for what it is. Until a way can be found to dis-include the black balaclava wearing miscreants all protests will be seen as illegitimate and worse, their message will not be heard. This kind of behaviour gives the jack-booted types licence.
So Harper's $1.2 billion dollar vanity project gets a black eye but he gets to make the claim (more plausibly than he otherwise would) that the violence justifies the enormous bill Canadians are footing for it. - Ontario's McGuinty get a share of the blame too for pushing through a bill when no one was looking that takes Canadian's rights away.