Stop. Just stop. While you may have originally found out about this guy's attitude via another source, once you are aware it is on Artists_Beware, you need to stop posting. It does nothing to help the artist get the money owed. All it does is pressure this person to move to another user name and get free art from more people before they realize who it is. In addition, harrasing people is against both LJ and FA's Terms of Service.
Consider this an official warning to everyone who has posted in the new journal. If a moderator sees you blatantly breaking the rule again, you will get a two-week ban from the community.