The Egg Riots in Leiden: Police protecting City Hall

Pupils from secondary schools all over the Netherlands were protesting about the obligation for schools to keep pupils occupied at school for 1040 hours every year. Because there are few teachers nowadays, schools keep their pupils occupied by giving them silly things to do. The pupils want to lower the obligatory hours. Today the protest turned a bit rioty: eggs were thrown. Eggs were the throwing object of choice at most of the protests.
more info: news.bbc.co.uk/1/hi/world/europe/7115847.stm