Property claims are nothing more than threats and negotiations

If someone 'owns' (an excess of) land this means that there is a perceived risk of forceful reprisals for people that venture to make use of the property. It is anti-social to make such threats if we have no legitimacy to do so. Someone who owns (or claims to own) an excess of land is making illegitimate death threats to the general population. We do not own land if we have no legitimate claim to it.