I'm not entirely sure if I'm in agreement with all of the above, however the relevant case law will vary by State. I am aware of some court decisions that prohibit an employer from searching employees' persons and personal belongings where they have an expectation of privacy - pockets, purse person, etc. That being the case, then it's possible that terminating an employee who refuses to have their person or personal belongings searched could be a violation of public policy, at least in the absence of a well-communicated company policy that states that such searches will be conducted by the employer.
A person, who is nice to you, but rude to a waiter, is not a nice person. (This is very important. Pay attention. It never fails.)