I watched "Grand Budapest Hotel" on a United flight, and they censored the scene where everyone stares at a nude painting. I thought they were staring at a blank canvas until we purchased the movie and saw the uncensored version.
Puts the scene into a whole different context.
On a separate note, I watched "Django Unchained" for the first time on an LH flight. Uncensored to the point of making me slightly uncomfortable watching that much violence on a plane.