when bitcoins will legal all over world i feel so banks will automatically start war, moreover it's not popular in comment man i means to say only 40% people hardly know by feature of bitcoin usage which make bank not thoughtful about bitcoins
It will be late for banks to start war against BTC then. They can only mess up with BTC when it is not legal and recognized in some country. And they will/are trying to prevent BTC from becoming official in any country.