Yesterday at 3:15 p.m. the man believed to be behind the illegal drug marketplace The Silk Road was arrested at the Glen Park branch of the San Francisco library. Known online as “The Dread Pirate Roberts,” Ross Ulbricht, 29, was apprehended after a monthlong investigation by the FBI. Ulbricht, who according to documents, lived on 15th Street in Hayes valley and frequented local internet cafes, is charged with money laundering, narcotics trafficking, and computer hacking conspiracy.

The Silk Road is a part of the so-called “deep web,” a vast network of websites that aren’t indexed by search engines, and thus can’t be found by them. The Silk Road was accessed by The Onion Router, or TOR, a free software program that encrypts user information and routes web traffic through a random circuit of relays, with the goal of making web traffic through TOR unreadable and untraceable. By using TOR, the Silk Road was designed to allow users to buy and sell everything from illegal drugs to firearms anonymously.

Purchases on The Silk Road were completed using bitcoins, a form of untraceable internet currency. While the value of bitcoins has fluctuated greatly over the past year, the FBI reports that between February 6, 2011 and July 23, 2013, over 1.2 million transactions were processed on The Silk Road, and roughly $1.2 billion passed through the site.

You can view the FBI’s criminal complaint here