Just read this report on a disturbance on a flight from Heathrow to Washington that had to be diverted to Boston.
So, here you are, sitting in a, say, Business Class seat for which you have paid big bucks. The staff are rude, the service is lousy, the headphones don't work and they have run out of your favorite alcoholoc beverage. Don't, what ever you do, complain. You may end up in Boston in handcuffs and legirons.