Hey when it comes to flying, I'd rather be safe than sorry. Turning off my Kindle is a minor inconvenience to me if it's just during takeoff and landing. I'm sure they wouldn't enforce this rule if it didn't truly pose a risk to the functioning of the plane. I don't understand the physics of wireless waves, so i can't say for sure. But I mean,
they even hand out iPads for you after the takeoff, so it's definitely not an issue that you use it except for takeoffs and landings.