Answer From a Teacher (Score 1)

I'm not an officially certified teacher yet, but one of the first classes you have to take in education training is a class on just this sort of thing; i.e. what a teacher has the legal right to do. Technically, since the teacher claims that the notes could be unfairly used in their class, the same rules could be applied that one would expect of a note being passed around in class. That logic allows the teacher to confiscate them. However, if the student, being a minor, were to get the support of parents/guardian, the in loco parentis rules that allow the former argument would be null. Thus, if you want you notes, complain to your parents!