You guys wasted 75% of the time insulting each other.
To me it could have been cleared up simply. Does Wenzel believe IP is justification for a state?
If he thinks it could be done with private contracts, and I suspect he does, then I don't think even Kinsella would disagree.
I think however the question is more general. Property is property by virtue of ownership. I had this argument with Dr Block, where he argued that things were property (unless they were superabundant).
I argued that things were not property unless they were owned, superabundant or not. Whether something is owned depends on whether it worth the cost to the owner to assert and maintain ownership. If it's not worth it to me to do so, it's highly unlibertarian to insist that the thing is still my property.
The example is a pond which is communally fished. You can have property in the commons, even if not superabundant, merely because it's not worth it to anyone to assert ownership.
I don't see IP as different in kind. It's just that the cost of maintaining ownership is much much higher and, in a statist society, there is temptation to socialize the cost onto your fellow man.
That's the part that's wrong.
If ITUNES can keep their IP secure, with encryption or some DMA they force a customer to use as a condition of use, then fine.
However if they fail, do NOT ask me to fund putting someone in a cage because you failed to do so.
If they fail then the IP in question is superabundant. Do not try to socialize onto me the cost of turning a now superabundant resource into a scarce one!