First you need to answer this question.
"Who has juristiction over the land or water being landed upon?"

It is NOT the FAA, because the FAA only has jurisdiction over airports
and in the air.
Ask yourself this, "who would give me a ticket if I was in a car on
this road and did something illegal"? It could be a state police,
county police, city police.

Now then, there are satutes, and there is COMMON law (which is law
based on what is commonly done, court cases etc). There are federal
statutes, state statutes and city statutes (and probably some others).

For private land, you could be considered to be trespassing, if you
don't have permission. There is Federal land, State Land, County Land,
City Land, Indian Land, private land and probably some others.

There are 50 states, probaby 2500 counties, hundreds of thousands of
towns and cities. All with different laws, some with no laws at all
regarding aircraft landing.

So there are lots of different rules, depending on where you do it.
LOTS!