Tuition is going up in England, and students react to the news. Generally speaking, this isn't really the way to get your point across. Passive resistance is usually much better. When you act so emotional and out of control, the message gets lost. Of course, I think the majority of these kids were simply looking for a reason to get violent and weren't really so concerned with the issue at hand.
This video shows a fire extinguisher dropped towards riot police from the roof of the building. It sounds as if the crowd of spectators on the ground begins to chant "Stop throwing sh**!"