Bitcoin has been the de facto currency of the Dark Web – the 'hidden' Internet accessible only by Tor – since the pioneering marketplace Silk Road, the 'eBay of drugs', arrived in 2011.
But just how much do we know about these new underground economies? Who is buying and selling – and what? Here's what available data can tell us about bitcoin on the Dark Web.
According to the FBI, Silk Road made a total of $1.2bn between 2011 and 2013. The marketplace is widely understood to be the fist 'killer app' for bitcoin, and drugs still make up a large proportion of transactions made using the digital currency today.