BT did a pretty good job for not being a lawyer. I have been a lawyer for
35 years and frankly the question rarely comes up.

In an emergency, you can land anywhere you need to land, period. However,
if you land in a military installation, you may regret it, because of paper
work. I would not land in a prison yard, either.

It gets more complicated. If you chose to land in a game refuge, for
example, that might be construed to be violating the FAR and there might
possibly be some sort of citation issued for flying over the area (since you
landed in the area, you were therefore not at a safe height or distance
away).

If you are intoxicated, there also might be a problem.

But, let us say you landed in an open farm field. Neither the owner of the
property or anyone else has the right to detain you. That would be false
imprisonment and you would have a claim for damages. The claim might buy
you a new airplane.

Each state may have various laws that apply. Generally, the owner of the
property would not have a right to detain the aircraft, but he may have a
right to keep you from trespassing to get it. Rarely will that happen.
And, if he is aware of some liability that he may be facing, then he is less
likely to be a jerk.

Your liability insurance carrier would be the immediate telephone call, as
they would assist in retrieving the aircraft.

Years ago a large Canadian 4 engine jet used an abandoned airfield to make a
successful landing after it ran out of fuel. Look up "Gimli Glider" for a
marvelous story. That may be one reason why the abandoned airfields are
still on the charts - because they are useful in emergencies.

Glider pilots land often in the puckerbrush and rarely have a problem. Most
of the time the farmer is excited to have a visitor from the sky - unless
the visitor is a jerk.

Colin