I suppose thats an argument munnyspinner, I wouldnt like to rely on it though.
Surely any passenger who 'self upgrades' will only take the seat space. I'm sure the Cabin Crew know who their class passengers are, and the upgrader is unlikely to get fed or watered in addition to nicking the seat space. (Id hope!) But if its not theft per se, it's what we used to call 'improper possession'.
