The Internet is without question one of the defining innovations of the past century; with such prestige comes peril. The articles in the cluster below are from the dark underbelly of the Internet, the sites and viral news stories that have subverted the Web for nefarious purposes.

Take MMORPG games like 'Second Life' and 'World of Warcraft.' While they've given countless computer geeks, tech whizzes and antisocial recluses a new way to express themselves online, they've also been the cause of a bevy of court cases. At least now there's a legal precedent that proves online and virtual cheating is still adultery.

Big-name sites like Twitter and Craigslist have each been used by criminals for nefarious purposes. Even prostitutes have learned to continue working in an environment that's far less dependent on the weather.

Check out some of the other ways the Internet has been used for evil below.