In a way, I disagree. These people object to the very existence of the American system of free enterprise and capitalism. They think because they are "enlightened", they shouldn't have to do anything as banal as working for a living - they should just sit around the neighborhood coffee house and have the government mail them checks. They are using the war as a pretext to express their anger at the United States in general, and to trash and vandalize the system they hate. The cause of "peace" gives them cover. And their leadership is well-funded by international Communist groups, even if many of the rank-and-file don't know that. It's the same bunch we saw protesting globalization in Seattle a while back - malignant professional slackers.
It's easy to see how the Nazi party got started in Weimar Germany. Germans were disgusted with this same type of leftist poseur trashing their streets and looked on in approval as the SA marched in to crack the Communists' heads. Let's hope these actions aren't a precursor to a similar backlash in America - I don't think they will be since at the end of the day, support for the protestors is tiny.