It varies from place to place. What you describe is, here in the US, generally called "adverse possession," but frequently it requires the "squatter", as you ca

It varies from place to place. What you describe is, here in the US, generally called "adverse possession," but frequently it requires the "squatter", as you call it, to make his intention to take ownership known (e.g. by placing a document in writing with the local government department that keeps real property documents). I see nothing wrong with this. Private property ownership is protected by the government, but almost always predicated on the assumption that the property will be put to use to the people it grants ownership to. Owners have the right to let their properties sit idle, but not without risk. This is a good thing: property is a finite (often arbitrarily and unfairly divided) resource. In my view owners have an obligation to put their property to use, and if I had the power to do so I'd make having idle property financially onerous (at best).