Silk Road was an online black market, best known as a platform for selling illegal drugs. As part of the Dark Web, it was operated as a Tor hidden service, such that online users were able to browse it anonymously and securely without potential traffic monitoring. The website was launched in February 2011; development had begun six months prior. Initially there were a limited number of new seller accounts available; new sellers had to purchase an account in an auction. Later, a fixed fee was charged for each new seller account.