I understand your concerns about losing access to certain items and this being unfair to certain kinds of buyers. In general though, the more options you give to market participants the better, and you have to think through the consequences of them not having those options to see the whole picture. For example, how many people saw the opportunity to sell on Silk Road and said "no thanks, too much exposure"? We don't know. How many have sold less than they could have because they wanted to stay low key? Again, we don't know. Even ignoring those effects, what will happen if a big vendor goes stealth. Well, new customers won't see their listings anymore and will buy from their competitors instead. These competitors will sell out of their stocks faster and until they can re-up will have to raise their prices. This is painful in the short run for buyers, but will act to attract new vendors with their own stock of the product. Prices fall, more vendors are participating, and for all intents and purposes, the market is stronger. Now instead of forcing all vendors to be public, we give them the option and the ones that want exposure can have it and the ones that don't don't have to, and the forces of supply, demand and the profit motive will incentiveize vendors to do what's best for themselves and their customers.