Diving Underground: Counterfeit Currency

Continuing with my research of the underground market, I stumbled upon a website which offers USD and Euro currency, at a discount of up to 75%. The payment is to be made via bitcoins (of course).

A screenshot of the website is pasted below. However, it does make me wonder, how the buyer could be assured of the legitimacy of the seller. Unlike ebay, there is no easy way here to give a negative feedback. Nevertheless, another insight into the thriving underground.