This is still a question nowadays because not all country gives a go signal for bitcoin. They are taking a lot of things just to slow down the growth of this currency. If not eliminate the whole system. What can you say guys.
Bitcoin poses no threat to the banking system in any state. Crypto currency only reduces the profit margins of bankers due to the fact that some people switch to using crypto currency and do not so often turn to banks. That is, there are still many financial issues, and first of all, obtaining loans that only banks can solve. At the same time, bitcoin can not replace the banking system, it is simply not for this purpose. And the whole of the crypto currency can not do this.
At the same time, banks have become virtually a part of every state and therefore the state will protect the banking system, up to the prohibition of the crypto currency, if the crypto currency starts to conflict with the interests of banks.