A crypto currency isn't a bank, but people that exchange crypto-currencies for money and back again are subject to financial regulations in most countries. For example, in the US I don't think that they would be considered 'banks,' but they would still be subject to Federal regulations. The point being that if you can convert back and forth you can use it as a way to launder money, so the government forces the exchange to have some sort of 'know your client' procedures in place.
