They seem to fail to mention BBSes, which is arguably the most important influence on the creation of the hacker underground, and IRC, which is today still the most permeable means to access it. They seem to breeze over MUDs/gaming even though that's a large part of what got people into BBSes to begin with.<p>From the early 1990s and on through the present, if you want to find out what governments are doing with your data, who has your credit cards and SSN, what the next major DDoS attack target will be, or get the dirty details [along with photo evidence] on the social lives of the most popular hackers, you go to IRC. To learn about the hacker underground they should be reading IRC transcripts.<p>Edit: I forgot about one of the newer and more exciting aspects of the cyber crime, hacktivist and hacker underground groups: web forums. Want to know who's planning Jihad on a Yahoo! Groups page? Want to know who's planning a "digital sit-in" (e.g. DDoS) alongside an Occupy or animal rights group? Want to get crack cocaine delivered to your front door (without using Silk Road)? Want to buy 10,000 US credit card numbers? Want to rent out a botnet of a million nodes for an hour? It's all on (somewhat) publicly-accessible web forums.<p>While we all like to play dumb that these forms of cyber-crime and vigilantism aren't "really hackers", they use the same techniques and often co-exist with the more "respectable" hackers. It's not uncommon for a more traditional hacker to live a double life (and make some nice coin on the side), committing a lot of the back-room crimes that someone else later gets caught for using. And it's just plain interesting to see how they all work.