Re: Prepare for...
The school was "Verantworlicher im Sinne des Presserechts", I guess (roughly translated as: responsible in the sense of publishing laws). The named party has to make sure that whatever is put on the homepage is legal. Which in this case it was not. A simple password protection on the website would have made it possible for the kid to pass this on to their grandparents / uncles / whatever. As I understand what was written, this would have been enough to kick out the court case.
(Another question would be if the kid would have even been allowed to enter into the license agreement with the copyright holder, which would depend on the kid's age....)