In the US, various Native American tribes exist as "sovereign nations," able to set many of their own laws that contradict those of the state. I'm not familiar enough with the law to know the limits of their sovereignty, but hypothetically a similar concept could be applied to any property hosting a node of the sovereign Internet.
Reservations in the US are a special class of enclave, which means a sovereign nation that physically exists inside another country. Other examples include Lesotho (contained within South Africa) or Vatican City (contained within Italy). What doesn't exist, and what I have a hard time imagining, is this sort of "distributed enclave" that's been suggested - an entity that exists in multiple places, each of which is within a different sovereign entity. It seems like a flimsy arrangement. Who's to stop any one country from taking over "internet territory" within their borders?
http://en.wikipedia.org/wiki/Tribal_sovereignty_in_the_Unite...