I think that's a bit of cultural bias there. Imagine a society without personal property, like some small tribe. Wouldn't they see our property rights as artificial? Maybe their "true" property would be something we don't even recognize like their honor or wife or other things they don't want to share with each other.

I have a wheelbarrow in my yard that I'm not using. Why can't anyone else use it? There's no natural reason why they couldn't. It's just there, they can take it and wheel dirt around in it. I might no even know it's happening, but my property rights say they're not allowed to.

I think the main feature of property is to disallow others from using it in a way that restricts your own use. For IP, others selling copies would restrict your ability to sell copies as they undercut you.

I wonder how you feel about medical information being free to copy? That's not property either, is it? Are you happy with no moral rights for subjects of photographs and no rights to privacy of medical information? Should patients "own" their medical records or should hospitals be free to use them however they like?

I think that's just an unfortunate consequence of overloading in the English language (and others, btw). One of the meanings of the word "property" is just "ownership" and has nothing to do with the physicality of the items under discussion. In Dutch, it's called intellectueel eigendom which translates as ownership, not property. When the Dutch "eigendom" refers to physical items, it's usually used in the plural (e.g. mijn eigendommen == my belongings).

Yes, that was exactly what I meant. Intellectual property is not property, and is therefore not private property.

The parent comment linked to "personal vs private property" on the page. The section specifically cites "socialist, Marxist, and most anarchist philosophies".