A person may not be presumed to have waived his rights, e.g. in signing an agreement not to sue before the fact, "click to continue," etc. A person does not indirectly waive his rights.A person most certainly can waive their own right, which is what a person does (in part) when entering a restricted area that they otherwise have no right to be. As you said, it's not the area that forces a person to waive their right, it's the person's choice to enter the area that does (in regards to the TSA, anyway).