as I read it, this was a decision made by MasterCard regarding the implementation of new policies and requirements in order to comply with the Patriot Act. MasterCard has obviously decided to set a new policy which takes this one step farther, and simply stop processing transactions for smaller adult businesses. Adult businesses which have a conventional business property, like strip clubs, multi-girl "corporate" websites etc. are able to obtain "credit card merchant accounts" from commercial banks, and MasterCard will still allow the processing of charges by these adult businesses. But single girl adult websites or any other adult businesses which are online-only and which do not own and operate a physical place of business are being left out in the cold. MasterCard's policies and regulations apply to ALL processing services, so there's simply no way around it. I certainly can't afford to buy a strip club in order to operate an adult business with a brick and mortar facility so that commercial banks will allow me to open a "merchant account" such that I could process both strip club and website transactions on MasterCards.
The alternatives this does leave open are "partnership" arrangements where the girl does not actually operate or control the website herself, i.e. PhotoClubs, IFriends, (fill in the blank)'s World, and other big boobs supersites. However, this means the girl must typically give up 50% of her website section's earnings to the actual website owners, or simply work for a one time modeling fee and giving up 100% of her website earnings to the actual website owners. This also means that a girl must typically give up decision making power in regard to the features/content her website section offers.
I guess the girls who have been avoiding the internet and instead concentrating on those $750+ an hour "private sessions" with fans in hotel rooms had a pretty good idea where the economic future of this industry lies. I'm not going to follow in that direction, so I don't know which direction my own future will take.