Driven by their primary emotions which are envy, resentment and hate.
A friend of mine sagely observed that the difference between conservatives and leftists is that we are creators and they are destroyers. You couldn't have a better picture of that than the contrast between the peaceful Tea Party demonstrators and the mobs defacing cities and causing millions of dollars in damage all over America and now the world. That's because the Tea Partiers love their country and respect their communities, even those they disagree with. Whereas the destroyers respect nothing and are driven by their primary emotions which are envy, resentment and hate.
Make no mistake about who these people are. This is the same global communist movement that attacked the World Trade Organization and "evil corporations" in 2001, and that took to the streets to defend Saddam Hussein and call Bush Hitler in 2002. The forces behind this movement are identical: Soros, the Shadow Party, gangster socialist unions and a "progressive" intelligentsia whose hatred of the capitalist West has caused it to lose its collective mind.