While noble in thought and a good overall idea, a recently article I read on blocking the computers or criminals is just something that seems impossible. The basic idea is that if someone is caught using a stolen credit card, their PC is blacklisted and will no longer be able to access any of the participating sites. The new service from Inovation is apparently quite adept at identifying who is who:

Identified fraudsters can change their name and password as much as they like, says company CEO Greg Pierson: As long as they continue to use the same machine, they can't get back onto the Iovation-protected site.
The big problem is, of course, the fact that a PC is so easy to come by. If someone is using stolen credit cards, likely it wouldn't be above them to get another one. The service does little more than modify the user's installation, which likely is something that won't be cross platform and would be wiped clean by a fresh install or a moveto a new machine. As far as most online stores are concerned, a new credit card might as well be a new person.