WIRED is running an article on the newest nuisance to the digital signage industry, that TV-B-Gone. Invented by Mitch Altman, an inventor with too much free time and an irritatingly overactive sense of social responsibility, the device can turn on or off basically any TV by cycling through hundreds of ON/OFF codes used by most major manufacturers (if you've ever programmed a universal remote control, you have some idea of what I'm talking about).
signage network owners aren't completely helpless, of course. The
cheapest and most low-tech solution to this problem is simply to cover
up your screen's IR remote receiver with electrical or duct tape, which
will render these rogue remote controls helpless. Of course, if
your screens are within an arm's reach, you can be sure that the tape
won't stay there for long, so think about an alternative solution, such
as disabling your screen's remote control receiver via a serial command
or keypress combo (many screen support this), or using a product like
our FireCast digital signage software to query the screen periodically to make sure that it's turned on.
I could go on, but I think that this post over at Gizmodo summarizes it best.