It is one thing to overbook (even if you lose customers if it happens too often). What is wrong is if you are pulling paid passengers, checked in and in their seats in order to accomadate airline employees. There is no savings for the airline in that case-- they lose as in United's case. Airlines should not have the right to break their common carrier contract with passengers to forcibly take them out of their seats in order to accommodate employee travel (they can book seats for their employees if they cannot plan well enough to avoid this problem-- maybe in coach instead of first class and that would also save them money.