"Julian Assange's investors are in the process of purchasing a boat to move WikiLeaks servers offshore in an attempt to evade prosecution from U.S. law enforcement, FoxNews.com has learned. Multiple sources within the hacker community with knowledge of day-to-day WikiLeaks activities say Assange's financial backers have been working behind the scenes on the logistics of moving the servers to international waters. One possible location: the Principality of Sealand, a rusty, World War II-era, former anti-aircraft platform off the coast of England in the North Sea. Based on a 1968 British court ruling that the facility is outside the jurisdiction of the United Kingdom, Sealand's owner has declared the facility a sovereign state, or 'micro-nation.'"

HOWEVER...

a long tradition of operating pirate radios has been to do it from a vessel on international waters.

Such a ship has no physical contraband to seize and they are merely violating local broadcasting regulations. Possessing "stolen" diplomatic messages ups the controversy to espionage, the later being something that might give a naval vessel in international waters the authority to board and search.

If you are beyond territorial waters and flying no flag to avoid legal responsibilities you must accept the risk that you also have far less legal protection.

To add to your doubt, the wikipedia article for Sealand makes it sounds like a couple guys with a boat and some small arms could over take it ... so, uh, you're moving your servers to a defenseless island? Where no other nation recognizes you? Where no one will come to your aid if someone decides to just blow you out of the water? And you're planning on hosting what? Oh, sensitive information about the United States government that they consider to be a threat to national security? Yeah, good luck with that. The US will take out anybody in Pakistan (or a number of other countries) in the middle of the night if they want to, I highly doubt they'd be worried about slapping some thermite to some servers out in the middle of the ocean and calling it a day -- which government would they worry about upsetting if they did so?