You're saying it's highly illegal to do usd-eur exchange. Do you also think it's highly illegal to steal ? What if the government steals ? Is that making stealing legal ? You know what happened to Cyprus recently ?
Legal/illegal - it doesn't really matter much. The only things that matters from the perspective of the policy and law makers are what THEY think is legal or illegal.
If a government decided it was illegal for you to buy grapefruits tomorrow, they could do so. Do you see the stupidity of this system ?
If a person has EUR, USD or any other currency, he should be able to exchange this with whoever he wants, whenever he wants, whereever he wants.
I agree with you, but that wont make your coins reappear once the government shuts down the website.