[Nepthu]

Well you don't have to answer any question that may incriminate you. And they normally can't search you without probable cause/reasonable suspicion by law. But an officer may search you anyways. Your real battle is in the courts. No evidence may be submitted to the courts that came from an illegal search. In practice I don't know how successful barring evidence due to illegal search is. Probable cause and reasonable suspicion may be open to interpretation as to what constitutes it.

Also Oski brings up a good point about private university property and I don't know how that works.