'.', the DNS root zone, is considered the property of the US Dept. of Commerce, so, no.
However, I could see a seizure of a domain in a different country's TLD (ccTLD to be specific) causing a diplomatic scuffle between the US and the foreign country. I can't imagine France would be thrilled with the FBI seizing 'foo.co.fr' or something.
Would that work in the face of caching? If my resolver already has .se cached, for example, it wouldn't consult the root at all when looking up thepiratebay.se, right?
However, I could see a seizure of a domain in a different country's TLD (ccTLD to be specific) causing a diplomatic scuffle between the US and the foreign country. I can't imagine France would be thrilled with the FBI seizing 'foo.co.fr' or something.