There have been various attempts to derive private property rights absolutely from some kind of first principles. I have not been impressed by them. It's not that arguments like this are obviously wrong, it's just that equally persuasive arguments could be made for almost any basic political position, including many that I want no part of.
No, I am prepared to accept that the law that you can't take my stuff the moment I turn my back on it is just another government regulation, not fundamentally different from the many that I howl against.
Given that property is not fundamentally a different kind of thing, why do I support it over the other ways that a society can organise its resources?
The root is that property is, relatively, very cheap and easy to enforce, compared to other possible rights. It is practical for me to take most of the responsibility for enforcing my private property rights myself, by keeping hold of my property and keeping an eye on it, leaving relatively little for the public sector to do. It is also relatively easy to work out whether I own something, compared to trying to determine, for instance, whether I most need it, or whether I most deserve it, or whether I can make the most productive use of it, all of which could be seen as "better" criteria for whether I should control it. Private property enables us to co-operate, not perfectly, but quite effectively, with a minimum of administrative cost.
With that as the basis of my support for private property, this quote by Lawrence Lessig has incredible power:
...the government has designed [the copyright system] so that there's no simple way to know who owns what, the very essence of a property system.