The rocking motion of trains is being put to use by Sony to protect the privacy of computer-using passengers (US 2004/0208394).
In a crowded carriage it is all too easy to read the screen of someone else’s laptop or PDA. Sony’s screen has a camera that looks into the eyes of the operator to follow the motion of their head as the train rocks back and forth. This information is sent to software that moves any text on screen in sync with that motion, so the image looks steady. But anyone trying to sneak a sideways look sees an image which is moving unpredictably, making…
