I know a lot of people will call this a conspiracy theory but the government will hire people within the protest to throw rocks and firebombs so then it turns into a riot and it's all dismissed.
This is an excellent video that shows how protests get dispersed by the government and people's rights get abused. It's a very entertaining watch even if you don't like this sort of thing.
I was not even aware of the G20 or anything.
-Everybody- should see this.
Thank you.