I don't think that it matters. It's my understanding that megaupload was entirely outside of the US. Their headquarters were in Hong Kong and the principal operators lived in New Zealand but the US still shut them down.
Well, they may have been headquartered and had all their servers in foreign countries, but they were still megaupload.COM, which means their domain was an American one. That’s why they were able to “seize” the domain, making the content unavailable. If the owners wanted to, they could have just registered another domain, say megaupload.nz, redirected their server’s DNS to the new domain, and 12 hours later, they would have been back up, just with a different web address. (That is assuming that the country where they were physically based did not cooperate with the US and seize their servers or cut off their internet connection)