Hackers (Crackers, system intruders) – These are people who attempt to penetrate security systems on remote computers. This is the new sense of the term, whereas the old sense of the term simply referred to a person who was capable of creating hacks, or elegant, unusual, and unexpected uses of technology. Typical magazines (both print and online) read by hackers include 2600 and Iron Feather Journal.
Phreaks (Phone Phreakers, Blue Boxers) – These are people who attempt to use technology to explore and/or control the telephone system. Originally, this involved the use of “blue boxes” or tone generators, but as the phone company began using digital instead of electro-mechanical switches, the phreaks became more like hackers. Typical magazines read by Phreaks include Phrack, Line Noize, and New Fone Express.
Virus writers (also, creators of Trojans, worms, logic bombs) – These are people who write code which attempts to a) reproduce itself on other systems without authorization and b) often has a side effect, whether that be to display a message, play a prank, or trash a hard drive. Agents and spiders are essentially ‘benevolent’ virii, raising the question of how underground this activity really is. Typical magazines read by Virus writers include 40HEX.
Pirates – Piracy is sort of a non-technical matter. Originally, it involved breaking copy protection on software, and this activity was called “cracking.” Nowadays, few software vendors use copy protection, but there are still various minor measures used to prevent the unauthorized duplication of software. Pirates devote themselves to thwarting these things and sharing commercial software freely with their friends. They usually read Pirate Newsletter and Pirate magazine.
Cypherpunks (cryptoanarchists) – Cypherpunks freely distribute the tools and methods for making use of strong encryption, which is basically unbreakable except by massive supercomputers. Because the NSA and FBI cannot break strong encryption (which is the basis of the PGP or Pretty Good Privacy), programs that employ it are classified as munitions, and distribution of algorithms that make use of it is a felony. Some cryptoanarchists advocate strong encryption as a tool to completely evade the State, by preventing any access whatsoever to financial or personal information. They typically read the Cypherpunks mailing list.
Anarchists – are committed to distributing illegal (or at least morally suspect) information, including but not limited to data on bombmaking, lockpicking, pornography, drug manufacturing, pirate radio, and cable and satellite TV piracy. In this parlance of the computer underground, anarchists are less likely to advocate the overthrow of government than the simple refusal to obey restrictions on distributing information. They tend to read Cult of the Dead Cow (CDC) and Activist Times Incorporated (ATI).
Cyberpunk – usually some combination of the above, plus interest in technological self-modification, science fiction of the Neuromancer genre, and interest in hardware hacking and “street tech.” A youth subculture in its own right, with some overlaps with the “modern primitive” and “raver” subcultures.