It's interesting that you say "some due diligence is required" and go on to put the burden of that diligence on Cliff, rather than the creator of the marketplace.
It should be pointed out that in a country like India or China it IS often the marketplaces legal responsibility to prevent counterfeit merchandise from being sold in their market. If you go into many malls for example there are signs up on the walls with a hotline to report people selling counterfeit merchandise. In India, they have a service you can contact that enforces returns/refunds of any counterfeit item that you purchase from a vendor (though usually mentioning the hotline and threatening to call it is more than enough to convince the vendor to give you a refund).
