Why don't Americans riot anymore?

I mean Canadians riot over a hockey game. What is it that keeps us from rioting in the way we used to or even having massive protests. There isn't a shortage of problems and it isn't like Americans as a whole are completely opposed to violence. The only people that seem to be doing anything are the tea party and they are pretty useless and I don't think they even know what they are protesting. I'm not condoning rioting, but it seems very odd that we haven't had any or even massive protests. You would think that a nation that was so adamantly for hope and change 4 years ago would be super pissed when almost nothing they were promised really happened. Granted I'm somewhat of an anarchist, but even if I weren't I'd still want some kind of change.