Under the heading of "things we wish we had thought of", observe as a clever hacker manages to take over any and all video screens in Times Square with only an iPhone and some video transmission hardware. Any video on the phone can be thrown up on a screen without any wires, overriding the video it is supposed to be playing.
This intrepid modder simply had to plug his video transmitter into the iPhone's minijack, and play a clip. By holding the signal repeater up to a screen, the video from the phone would play on it. The crazy thing is that the powerful repeater can even paint the video signal on the giant screens above storefronts in Times Square. All that was requited was a balloon to get the repeater within range.
This is a totally awesome demo, and the developer says he will work on making the repeater more stable to avoid breakups on larger screens. Still, we have to wonder what's going to happen if this technique becomes widespread. No screen would be safe.