We had an incident a few years ago with a student and instuctor doing steep turns and the winds aloft carried them near a nuke power plant, when they realized it they broke it right off. When they got back, the were numerous police cars and FBI waiting to take them in. If it was not for the ATC controller knowing the CFI they probably would have been arrested. He was able to talk to the FBI while they were instructed to hold on the airfield. He convinced them they were not terrorist