When an East German was able to escape to West Germany he/she was completely free of the East's shackles.
Additionally, 15 USC § 78c(a)(17) states:
interstate commerceI don't think that the "exit tax" will stand up in court. Indefensible.
(17) The term “interstate commerce” means trade, commerce, transportation, or communication among the several States, or between any foreign country and any State, or between any State and any place or ship outside thereof. The term also includes intrastate use of (A) any facility of a national securities exchange or of a telephone or other interstate means of communication, or (B) any other interstate instrumentality.