Isn't the whole point of bitcoins to get away from that kind of thing though? Someone has to maintain a list of what is 'dirty' and that maintainer becomes a c

Isn't the whole point of bitcoins to get away from that kind of thing though? Someone has to maintain a list of what is 'dirty' and that maintainer becomes a central authority in the market. And, as I understand it, part of the philosophy of bitcoins is to have an open and free market. So while your idea is theoretically possible, once things like that start I fail to see how bitcoins are different from any other currency.