Even if there were some mechanism in place to blacklist people, you'd never get the entire industry to adher to the blacklist.

First, how would everyone find out about it? Only a small percentage of webmasters come to these boards.

Second, you'd always have people breaking ranks to make money. Webmasters would either promote them to take advantage of the lack of sites promoting the offender, or sites who were already making a ton of money off said site would be very unlikely to give that money up.

Probably the easiest way to blacklist someone would be to get both of the top billers to stop processing for them. And I don't know how you'd achieve that. They would clearly have to have broken the law.

Michael