Although I am not an Obama support, didn't vote for the dweeb, I have to say these kind of riots by students and youths have been around for decades. These youths are anti-capitalist anti-authoritarian anarchists and hooligans, mostly youths and students are involved behind the riots. They are nuts, I think they are crazier then the 'muzzies' and more destructive because the authorities are reluctant to use mega force against them. When they are done European and North American cities look like they are part of war zone areas.
French Anarchists Riot 2006
Berlin Anarchists Riot
Anarchists Riot in Italy, Bulgaria, Sswitzerland, Norway, Belgium, France, Nederlands
Anarchists Riot in Germany / Rostock (G8)
Anarchists Riot in Barcelona
Anarchists Riot in Gothenburg, Sweden
Anarchists Riot in Stockholm 2006
Anarchists Riot in Athens, Greece 2007
Anarchists Riot in Italy, Greece, Germany, France, Denmark, Latin America
Anarchists Riot in Poland
Anarchists Riot
BTW, most of these 'students' who are rioting come from well off families. The kid who was killed Saturday went to one of the most famous, expensive and prestigious private schools in Greece, Scholi Moraiti/Moraitis School.