There is some valid concern here, but not all that much. For law enforcement to make an arrest, or even issue a citation, the cop would have to actually see you exposing yourself. Otherwise the trucker would have to pull over when the cop stopped you and fill out a formal complaint. Then he'd have to show up later in court to testify about what you were doing and, believe me, they're way too busy trying to make a living to waste their time with criminal complaints and court appearances over such a trivial offence. But with the proliferation of cell phones these days it's the reason I don't flash truckers much anymore. If one of them were to call it in it could still result in the inconvenience of being pulled over and questioned. .