It is clear that the credit card companies have a lot to lose should Bitcoin gain a foothold in the global economy. Indeed, there are articles out there already the cite anti-bitcoin vitrol coming from this direction - http://www.teribuhl.com/2013/10/22/mastercard-hates-bitcoins/

One question that has always concerned me is this: Do credit card companies have the legal power to refuse their services to businesses that also accept Bitcoin for payments?

My understanding is that if Bitcoin was a company as it stands this couldn't happen. Anti-trust and anti-competitive laws is various countries would prevent credit card companies from taking such an action but in the case of Bitcoin we are dealing with a technology that has no central authority and only quasi-legal recognition to date. Should the big CC companies decide to play hard ball and dictate take-it-or-leave-it terms to businesses do we really have any recourse here?

We already have a major global player - Apple - refusing to allow Bitcoin transaction related apps on their iOS platform. If they can do this, what is stopping the global credit card players from taking a similar stance?