The flight was not overbooked, it was full to capacity. Then, United suddenly 'added' 4 of their staff that 'had to be' at the next city to crew a flight there, right before takeoff. Their small print makes that 'legal'.
Shit, you're right. Even so, it was a random selection and if he had just left the plane, there would be no problem. I agree the police were being dipshits, but the airline really isn't the issue and is getting a bad rap.
Meh - bad rules and things that make it 'rough' for 'us' the little guy customers - should be fought against. Doesn't make the guy right but hey, 'change' isn't always painless. That one guy being steadfast, might (not likely) make things change abroad. (Squeaky wheel scenario and all) ;)