Internet and digital technologies have been discussed recently by Addiction contributors in relation to the delivery of efficient computer-delivered brief interventions [1,2], online methodologies for recruiting and surveying illicit drug users  and the internet's role in facilitating the spread of information and sale of emerging drugs such as mephedrone  and synthetic cannabinoids .
Here, I introduce readers to a novel use of the internet in the drugs field. The anonymous online drug market-place Silk Road was first revealed in June 2011 . Silk Road is accessible only to people who are using Tor anonymizing software . Tor uses encryption to make it impossible for anyone to trace IP addresses (the electronic code assigned to each computer on the internet). The front page of Silk Road looks a great deal like the front page of eBay. Goods and services for sale are categorized and all manner of drugs are available under the following categories: ecstasy, cannabis, dissociatives, psychedelics, opioids, stimulants, benzodiazepines and other. Sellers receive ratings from buyers and comments about the quality of their products, how fast they ship and the level of professionalism and discretion of the transaction. Trust in sellers is built on reputation. Silk Road traders use the anonymous currency Bitcoin . This decentralized international currency operates through peer-to-peer technologies.
At the time of writing (October 2011), Silk Road is still online and continuing to expand. Facilitated by a combination of the internet and encryption technologies, buying and selling illegal products is now possible and may increase dramatically in the future. What may stop an exponential increase in the use of anonymous online drug market-places is the hurdle of delivery. At the end of the transaction, the physical product still needs to be sent to the buyer. Sending products between countries allows law enforcement the opportunity to intercept packages and potentially attempt to arrest the would-be importer. Sending products within the same country may make arrest less likely. There are also numerous barriers to entry for people who might want to use Silk Road. Installing and using Tor, buying and using Bitcoins in a secure way and taking the risk of fraud or arrest upon delivery may deter the majority of would-be users. Nevertheless, for the minority who master these concerns and are willing to take the risk, Silk Road has revolutionized how the internet can be used to source drugs. After all, buying drugs in the real world also involves considerable risk. For some, the online equivalent may prove more convenient and secure than arranging a standard deal.
There are many unanswered questions about Silk Road. The extent to which law enforcement can stop and disband a site such as this is yet to be seen. The extent to which drug users will use this new technology is also unknown. Needless to say, if anonymous online drug markets do end up expanding into mainstream drug markets, they will pose a real challenge to existing drug laws and policies. We should definitely watch this space.