Turns out, the laptop has a built-in motion sensor. Nominally, it's there to protect the internal hard drive. The basic idea is this: If the accelerometer suddenly notices that the gravitational pull of earth is no longer present, the most likely explanation is that the laptop, sensor and all, is currently accelerating at 9.81 m/s? towards said earth. In that case, it will (wisely) try to turn the hard drive off in preparation for impact. It can, however, also be used in situations not involving lobbing the laptop across the room, fun though that may be.
