LCDs don't generally suffer from image burn-in right? Well, the other day I had a malfunctioning DVD player connected to my LCD monitor: The fault caused the picture to judder up and down at 50Hz by about 10 lines. To my suprise after 5 minutes displaying the juddering image I had severe burn-in Switching back to a flat field the juddering image was clearly visible as a flicking shadow. Fortunately this slowly faded after an hour on flat field. But it might have been more serious if I'd displayed the juddering image for longer. Turns out that some LCDs use a drive scheme which inverts every field. If your image changes from black to white in exact anti-phase to the inversion scheme you get burn-in. ( Caused by electrolysis in the LC. ) So in theory a broadcast flashing black-white image could damage millions of unattended LCDs across the land. OK, so it's pretty unlikely to happen - but worth knowing just in case.