An off-duty police officer, familiar with traffic speed checking devices, drove through a school zone within the legal speed limit.
Suddenly a flash of a speed camera blinked, taking a picture of his license plate. The officer, thinking the camera was in error, drove by again; even more slowly. Another flash.
He did it again for a third time, at an even slower speed. The same result. “this guy must have screwed up the settings, ” the off-duty officer thought.
A few weeks later, when he received the violations in the mail, he discovered three traffic tickets: each for not wearing a seat belt!