Any place - including ebay - where people sell used goods is a possible place to sell stolen items. In my opinion, Ebay is less likely to be an outlet for stolen goods because it costs to list and sell there. payment for the goods is not in cash. And the seller can be located rather easily unless it's a bogus account in which case - no history-no feedback - so you can tell. While you can undoubtedly purchase stolen goods on Ebay, I doubt it's a haven for stolen bike parts. At least not stolen goods sold by the thief himself.