Ebay is better then on here! I had a scam buyer on here too, because people are less likely to leave a feedback on RCU. On EBay, you can block those that don't have 100% positive feedback from bidding on your item. You can also delete the bids of anyone that you don't feel worthy of their bids on Ebay, and block them from further bidding. Hopefully, your tank isn't that expensive and lesson learned. Not EBay's fault that a faulty bidder bought your item. How was his feedback? If it was poor, kind of your fault too for letting him continuing the bid. Just my experience, and I have over 550+ 100% transactions on the Bay.