I have written about the anti-CPE riots because I was in Paris while the worst of them were taking place. The picture above is one that I took. Here is a brief history of how this political manifestation came to be:
Who: Young students from all over France protested the CPE (see below) for its unfairness, in hopes that prime minister Dominique de Villepin would withdraw the contract. Rioters had few inhibitions while exhibiting their anger: cars were set on fire (I had the interesting and somewhat frightening opportunity of watching one burn), tear gas was released (I also had the experience of inhaling some on two different occasions), streets were congested so bad that no traffic could move in some areas of Paris.

When: The riots took place during the third week of March, 2006.

Where: Rioters manifested themselves in many large cities in France, including Marseille, Lyon, and Strasbourg, but Paris saw the largest number of protesters (see graph below).

Why: The CPE (Contrat Première Embauche) allowed employers in France to terminate their workers’ sessions without a valid reason if the employee was under 26 and had been working for the employer for less than two years. The purpose of this contract was to keep recycling older workers for younger ones in order to save money. The anti-CPE riots are reminiscent of the riots in Paris in May 1968 following the closing of one of the Sorbonne universities.

Now: A month later, the CPE was withdrawn on April 20, 2006 to be rewritten.

Additional Resources
Read the CPE (in French)
Dominique de Villepin’s Biography