Bzzzzttt!! WRONG. Turn the key a little bit and it kills the engine, but you still have complete control of the vehicle. You have to turn the key all the way to the off position to lock the steering. Of course, killing the engine causes its own problems -- it is VERY difficult to steer a large, heavy vehicle without power steering and you only have enough vacuum reserve for a few pumps of the brake. The power steering problem is going away as electrically-assisted power steering rapidly takes over from hydraulic ps:
Yes, let’s ask Hastings about how well having an electric motor control your steering works. Better, let’s ask Barnaby Jack...