It did not start off as an unowned resource, and it is not scarce. Scarcity is what creates the need for property, as it is the source of dispute. If I steal your physical book, you can no longer make use of that book. But if I infringe on your copyright, you still have the original book, and the book-pattern, the symbols in a particular order that form a story. Stephen Kinsella calls these "ideal objects" in his short paper Against Intellectual Property. As they do not fit into the category of property, my questions stand.