I like this idea.One thing I really enjoyed about several forums I used to be a member of, automotive and record collecting/tape trading, were the stickied rip-off alert threads.
If you shipped another forum member a cracked header and refused to replace it or accepted a payment but never shipped a tape or record your info was added to the list of offending posters with links to the listings and any complaint threads that arose from your fraud.
Egregious cases or repeat offenders resulted in a permaban with the users' Paypal, ebay and shipping info posted to prevent them from sockpuppeting their way around the ban.
Otherwise the user was free to continue using the forums, temporarily banned from the marketplace subforums and allowed to eventually rebuild their reputation.
I believe that such action was attempted with the Goddess Patty situation on the paysite board. It looked like the poster that made the report was wrongly made the bad guy. It seemed like a blind eye was turned to the complaint