Of course you can. A legitimate business person refuses to accept business from someone who has committed theft and fraud. You don't just turn a blind eye to it just because it didn't happen on your site. Actually, in this case, it did happen on CTCW too, but instead of doing the proper thing and kicking this guy off, he got another chance. There is no law or regulation requiring Chase the Chuckwagon or any other website to accept anyone's auction listings.
I'm sorry, but this whole thread has really enraged me since I had pretty much just let it go and written off the loss, but the refusal of CTCW to do the right thing here and purge sellers who have ripped off people in our community is completely unacceptable. It would be one thing if CTCW had no idea about this situation, but it has become very clear that CTCW's management has been actively working with this guy and knows about his past and current issues. As far as I'm concerned, my mission from this point on is to get out the word that Chase the Chuckwagon is fine with harboring people who have committed such terrible acts on Ebay that they have been banned. Do you even know how hard it is to get kicked off Ebay?
No sense in arguing with someone that knows they are right (sarcasm)