It seems like the best reason in this case would have been very straight-forward: "I've landed in the U.S., already cleared customs and immigration, and have no plans to board another flight. I simply want to leave the airport and do not consent to having either: a) being the victim of a sexual assault; or b) walking through a nude-o-scope as a pre-condition to exiting the airport. Neither will I consent to being detained-- I want to leave the airport now; what guidance can you offer as to how to leave the premises?"