-- Oh shit. It really is the empire. According to http://www.techvisas.com/taxation.htm Taxation of Aliens who Have Departed - Anti-Expatriation Rules. Aliens who live in the U.S. as residents, irrespective of visa status, face special anti-expatriation rules. Such rules were formerly applied only to U.S. citizens who cancelled their U.S. citizenship in order to be free of U.S. gift and estate taxes. As a result, termination of lawful permanent resident status after several years will result in continuing liability of the foreigners gifts and patrimony (assets) to U.S. probate and estate taxes for 10 years after such termination