Willfully displacing or destroying a survey monument might seem like a way to (unethically) gain some property.

It would be an illegal one.

In Pennsylvania, meddling with a monument to “call into question a boundary line” is a misdemeanor of the second degree.

Other examples of misdemeanors of the second degree include: bigamy, a second offense of retail theft — value under $150, strangulation (not in a domestic situation), resisting arrest, recklessly endangering another person, and institutional vandalism — up to $5,000.

Such crimes carry maximum possible terms of two years in prison and fines of up to $5,000.