Why do people act a fool when they know the camera is on? Jumping up and down, making stupid faces, holding their babies up in the air, picking their nose, holding up religous quotes i.e John 3:12 (or what ever), making peace signs etc... Do they really think the viewing audiance gives a fuck? Do they really think that some major motion picture exec will discover them? It's silly to do that, why do it? Why act an ass on a program that dosent invlove you? 
