I think you should more clearly describe what you're claiming. How exactly are they manipulating?
If banks can just control the price, sure they would do it. But the first question is: how? Just shorting futures isn't per-se an answer - that trade would only go in one direction, and Bitcoin is currently way way too small to actually let big hedge-fonts make meaningful trades. Additionally, someone has to pay the other side of the trade.
The next part is that they would all have to conspire together to make this work. The next part is that it would be much more profitable to manipulate the price up, if they can. And the next part is that Zerohedge is absolutely in no way any sort of reliable source.
Bitcoin does not belong to anyone, just like the Internet or the technology on which e-mail is based. Banks can not control them. Bitcoin can be used by anyone who follows the rules of this payment system. The creator of Bitcoin, which is hiding under the pseudonym Satosi Nakamoto, also does not regulate the network. Governments are wary of cryptocurrencies, as they cannot regulate the movement of capital, including abroad. The main claims to technology are that it allows paying for illegal goods, laundering money and financing terrorists.