My wife told me an amusing story about those white plastic motion sensors you see in modern homes these days. They're little boxes with a sensor and a red light. When the sensor sees motion in the room, the red light comes on. If the thing is hooked up to a burglar alarm, then it will raise a klaxon. When folks are at home, though, the alarm is off, so the red light sliently goes on and off on its own.
The story involves a particular mom who was on the edge of losing control over her children, who were becoming increasingly hyperactive what with the upcoming Christmas holiday season.
Mom patiently explained to her children that the white boxes on the walls were actually cameras from the North Pole. When the red light comes on, that means that Santa is watching you.