[greensoap]

That is because tenancy has a depth of laws surrounding them. The only way to kick a tenant out of his house if with an order from the Court and action by the sheriff (at least in most states). But your right to stay on the property of another person, outside of tenancy arrangements, do not have that body of law.

[srtjstjsj]

Airplanes also have a depth of laws surrounding them.

[gyc]

You are absolutely correct that a whole host of laws govern the landlord-tenant relationship. Given how regulated air travel is, as well as United's status as a common carrier, I wouldn't be surprised that there are also similarly restrictive laws for air travel, so I still question whether Dr. Dao did have a duty to vacate his seat despite the breach of contract by United.

[kelnos]

The actual lawyer who wrote this article believes Dao did have a duty to vacate, so I think that's a bit more authoritative than our layperson opinions here. Of course, only a court could really answer that question, and I'm sure United will try hard to settle this out of court.