When in school, i used to borrow books from the library at school and from a private library. During test times or when i was found to be pouring over novels all day long instead of reading my text books, my parents hid them so that i could concentrate on my studies. I remember i used to search for them on the sly. This process occurred a few times until they found out that the concealing-books bore no result.
I don't think they spent much time choosing a secure place which was out of my reach. So i used to discover the book more or less in the same place. It isn't difficult for a child to defy or outsmart it's parents' during some instances. Eventually the game stopped.