The Dark Net: Inside the Digital Underworld

The Dark Net: Inside the Digital Underworld by Jamie Bartlett,

Bartlett explores the use of the Onion Router (TOR -a system that enables users to communicate anonymously on the internet) and shows how the use of TOR and unindexed webpages facilitates everything from pro-anorexia groups, to illicit drug marketplaces, to bitcoin proponents, to suicide support  and child porn websites. An interesting look under the hood of the internet with interviews by the author of all sorts of people caught up in their own section of the dark net; trolls, programmers, drug dealers, and those with extreme views.
An interesting read.