What are the legal issues when entering school areas while searching for geocaches? Some caches are located in such places. The first is available without problem for children and teachers, but what with other geocachers? Is it actually legal to go into such area without "strong reason" such as working there or beeing a parent of a child? In worst case, how to react when the police is called?
The question is focused on Europe, however the answers about US would also be appreciated, because there are many law similarities anyway.