Indeed. In a sudden deceleration an i-pad could be very lethal. Given the thinness of them, in the right orientation as it hit a human it could be very nasty. I'm reminded of the story of the death of a sales rep in a company I worked for some time ago. He died long before I joined them but he was killed in a car crash when an item weighing only about 1kg was propelled off the back parcel shelf and hit the back of his head. I recall it was said the inquest had concluded he would have survived the crash had that item not been on the back parcel shelf. The company had a strict "everything must be stored in the boot" policy after that when out on company business in either your own or one of their vehicles.