I have, that's why I consider it an open debate and not a settled matter. :-) Geoism is a great example because we created the products of our labor, but not the land on which they rest.

The Lockean Proviso says we just need to leave enough for others, but there's no longer any livable unclaimed land left on Earth. If there's no place left for anyone to realistically homestead, then every landlord is violating the NAP. We can't just disappear into the woods and be left alone anymore - "you're camping on private property".