I think it's pointless to argue about it in that way, though. If you can think of a supposed example (or more than one) of a monopoly that doesn't derive from government power, I'll either explain to you why that's not the case, or concede the point. I scanned at the list of examples on Wikipedia briefly, and didn't find any "free market monopolies."

[1] http://www.amazon.com/Capitalism-Treatise-Economics-George-R...