These rules would mean something if they bothered to train their screeners. Just this week I got conflicting direction about iPads, and that was at Chicago O'Hare and Detroit Metro, two busy airports.
It seems that nobody worries about phones and kindles, and anything that is laptop-sized has to come out. The iPad seems to be the point where the confusion starts.
Considering how popular the iPad is, it would be nice if there was a consistent, definitive answer.