[luckylion]

If it doesn't grant them exclusive rights, and they can't e.g. put up "no trespassing" signs, wouldn't that be a crime because they are claiming ownership, and thereby claiming that the state does not have ownership? Have you ever reported one of them to see what happens?

[phpisthebest]

It is only a crime if police and prosecutors are willing to enforce it.

Sadly today too much of the law is political, both left and right, with police and prosecutors choosing what laws they want to enforce, when, and on who (i.e picking people or groups they dislike)

[standardUser]

Not uncommon for large landowners to be on friendly terms with local politicians and law enforcement.

[GavinMcG]

What crime would it be? It might be dishonest and antisocial but those things usually aren’t criminal on their own.