Just a very short summary:
During a hot and sunny day the protest started peacefully without incidents. A Mix of students, pupils, union members from all over germany participated. Despite the heavy police presence the mood was quite good. After the closing rally at the Opernplatz hundreds decided to go and block the city highway (a common practice in the last monts/weeks). At this point the cops started to attack the demonstration with clubs and pepperspray and many were arrested. It was by far the biggest wave of arrests at a student demonstration in the last months, as the level of repression rises more and more.