I just posted this on another thread but it's relevant so what the heck:

What the banks are truly terrified of is money laundering and sanctions. Several major banks have been fined many billions of dollars this year over not doing what they should in this area. As it stands the bitcoin world just isn't up to scratch in complying with these rules. If a bank facilitates it they are liable.

So my guess is that some banks have decided that the risk profile of any bitcoin business, especially ones that provide bitcoin to fiat exchange, are too risky to deal with.

Those that are well backed and have professional staff and controls that are proven to be good enough (maybe coinbase say) will get an exemption.

It seems harsh but honestly it's how the entire financial system deals with any money broking business. I've seen it first hand because I've consulted for companies and banks to help them comply with the rules.

As bitcoin matures and becomes a serious medium for wealth transfer this kind of thing is going to step up. In the big scheme of things it's maybe a good step toward decriminalizing the currency and helping mainstream adoption. But it's a shame if it's shuts down some entrepreneurialism as a result.