Dark Web

 Lev Grossman and Jay Newton-Small have a Time article about that other Internet:

On the afternoon of 1 October 2013, a tall, slender, shaggy-haired man left his house on 15th Avenue in San Francisco, California. His two housemates knew him only as a quiet currency trader named Josh Terrey. His real name was Ross Ulbricht. He was 29 and had no police record. Dressed in jeans and a red t-shirt, Ulbricht headed to the Glen Park branch of the public library, where he made his way to the science-fiction section and logged on to his laptop— he was using the free wi-fi. Several FBI agents dressed in plainclothes converged on him, pushed him up against a window, then escorted him from the building.
The FBI believes Ulbricht is a criminal known online as the Dread Pirate Roberts, a reference to a character in the book and movie The Princess Bride. This Dread Pirate Roberts was the owner and administrator of Silk Road, a wildly successful online bazaar where people bought and sold illegal goods; primarily drugs, but also fake IDs, fireworks, and hacking software. They could do this without getting caught because Silk Road was located in a little-known region of the Internet called the Deep Web.
The Deep Web is a specific branch of the Internet that's distinguished by that increasingly rare commodity: complete anonymity. As such, it is a vital tool for intelligence agents, law enforcement, political dissidents, and anybody who needs or wants to conduct their online affairs in private, which is, increasingly, everybody.
But some prosecutors and government agencies think that Silk Road was just the thin edge of the wedge, and that the Deep Web is a potential nightmare, an electronic haven for thieves, child pornographers, human traffickers, forgers, assassins, and peddlers of state secrets and loose nukes.
Read more here. 

Rico says he still doesn't understand how it works, but it's fascinating...