On May 1st you can see burning cars in Berlin, too. It's not a "French thing".

Unfortunately it's the youth's way, who are descents of Maghreb immigrants, to express their hate against government and society. In their weird way of seeing life and their environment that's the only way to do so.
Also governments become more and more "overprotective" and suppressive these days and act very very strict with such "troublemakers".