Ownership is a concept. It is not an observable phenomenon, existing apart from the minds that believe in it (and the objects which those minds might fashion to make the concept more solid). There is no ownership apart from minds.
As a concept, it is subjective, which means that when one is talking about ownership, one is talking about a particular view of ownership and not something observable, objective, or absolute.
This remains true no matter how much consensus amasses over what ownership is and is not.