Except that's still not a good analogy because that involves the personal property of a discrete individual, not the somewhat public service vehicle of a faceless corporation. We shouldn't allow corporations to run roughshod over the little man. Just because civil suits exist as a potential route for renumeration doesn't mean we should allow this behavior from airlines in the first place.
The trespassing is in their jurisdiction to enforce, as it is a crime. Being shorted on a ticket is not in their power to address.
It is bad when you get stuffed by a corporation, but it’s no excuse to break other laws.
https://www.transportation.gov/individuals/aviation-consumer...
That said, the rule seems to be that once you've boarded, they need specific reasons (behavior, safety, etc.) to remove you from the flight. In this instance, it sounds as if the airline fucked up.
Especially if you have wilfully ignored the terms of service and caused disruption to other passengers.
> if the gate agent accepts a passenger for boarding after collecting or scanning the passenger’s boarding pass, the carrier is prohibited from removing the passenger from the flight thereafter.
That is precisely what United did.
If United rented out their house to two tenants, they can't just drag one of them out by the ears? It's on them for being two-timing fraudsters.