Anarchy, State, and Utopia/ownership
From Critiques Of Libertarianism
It will be implausible to view improving an object as giving full ownership to it, if the stock of unowned objects that might be improved is limited. For an object’s coming under one person's ownership changes the situation of all others. Whereas previous they were at liberty (in Hohfeld’s sense) to use the object, they now no longer are.
Robert Nozick, "Anarchy, State, and Utopia"