Imagine this - you are on a flight playing Angry Birds on your iPad and can't get even one hit right. Your embarrassment is doubled by the person sitting next to you watching you screw up the game. Well, Steve and his team thought of this back when iPad wasn't out of Apple's headquarters. Back in 2009, Apple had filed for a patent at USPTO to let your switch your LCD screen viewing angle so that the unintended viewers wont' get a chance to look what's on your screen.
According to the patent filing, the LCD screen would have a steering module made of special material to aim the scattering modules that sit on the top of them. The top layer would redirect the light emitted from underlying diodes making it possible for the user to limit the viewing angles. The patent specifically mentions cellphones and laptops, but not tablets. There is no official word on when will Apple secure this patent and we'll get to see this in action.