I always have the same fear when using my laptop on the plane. Though I've never been too concerned while seated in F. In coach, where there is a little lip on the seat back where the tray comes out of, and where space is soooooooooooo tight, I am always paranoid that the person in front of me will quickly recline the seat, catch the top of my laptop screen and snap it in half.

For that reason, I always keep my screen angled back toward me so that it won't get caught in the lip. It makes it difficult to see the screen, but I'm not taking the risk.

This is also the reaon that I never recline my seat in coach unless I'm on a night flight where everyone is sleeping. And even then I look first, then recline s-l-o-w-l-y.