> If you stop being their customer, they will have just to live with that.
That's precisely the theory behind free governments the world over, to wit: "Governments are instituted among Men, deriving their just Powers from the Consent of the Governed". Except we all know in practice there are barriers to withdrawing consent from the government, just as there are surely barriers to leaving a market.
MtGox certainly is not central authority. If you stop being their customer, they will have just to live with that.