On a college campus, in the dorms, nothing is your private property. The room belongs to the university, and as such, they can search anything and anywhere they want to. An RA here(in Oregon) told me that if you own something with a lock on it, it IS your private property, and the RA can't search inside that, and can't make you open it. Unfortunately they can call the cops, but they will have to have a warrant to make you open the thing with a lock (box, refrigerator, whatever) and hopefully in the meantime you can find a way to get rid of whatever you don't want them to find.