There are students who may have things inside their locker which may be a weapon, drugs, or something private. On the other hand, students should keep what they have private at home. It's better keeping their private stuff home safe and sound because if an administrator or principal checks his or her locker, what they have will no longer be private, but will be their one way ticket to trouble-mania. How ever, if it's a weapon, the student can end up with a never forgetting suspension or can end up with the biggest detention ever. Even though, students have the ability to steal stuff from other students like notebooks or agendas. With locker searching, the robber can be caught and it's bye bye robber.
Of course they should. Why would you deny a locker search unless you were hiding something illegal or against the rules in your locker? And don't tell me that you have private things in your locker. There is no reason to be keeping your diary or journal in their. If you really have something private then keep it safe at your house. Would you rather have the principal see pictures of you and your boyfriend in your locker or be ensured that there isn't any kid concealing a weapon in their locker, ready to start a gun fight? And really the locker belongs to the school. They pay for it and maintain it. By putting your stuff in their you are pretty much borrowing a space that they loan to you. If your keeping things in their that they wouldn't want in their then of course they have the right to see what it is.