So if you pop in a DVD "infected" with Protect DVD-Video, it can't be read by Windows Media Player, Media Center Edition, or any DirectShow-based software, thanks to a Universal Disc Format that tricks your machine into believing that the IFO file is zero bytes long.
Until recently the only equipment for spotting a suitcase bomb was an unwieldy machine the size of a refrigerator, using liquid nitrogen to cool crystal detectors down to 300 degrees below zero and taking hours to produce a reading.