I don't see how a metal detector has anything related with pircay. :B IF the night-vision googles have built in recording capabilities, then I doubt anyone would like to see a black & white (or green) recording. Watermarking will have no effect on current camcorders and playback equipment, so this will not prove effective until some years to come when every piece of video equipment supports watermark detection. If they really want to stop people camcording in the Cinema, they would need to put something in the picture that inteferes with the camcorder. An article on Afterdawn mentioned a technique that varies the frame rate, but the varying flicker will be annoying to the viewers as well. My idea would be to shine infra-red spotlights randomly over the screen. While we cannot see infra-red light, Camcorders can pick this up. For example, try zapping a TV/VCR remote at a Camcorder or webcam and the remote's infra-red LED will look like a flickering bulb in the recording. Anyway, how many male people would take their wife/girl friend to a computer screen and to watch a low quality picture movie with mono sound?