One group that is often subsumed (notably by the media) under the hacker label, is phreaks. Phreaking started with the Yippies! (a radical political off-shoot of the hippies). Abbie Hoffman’s Steal This Book: A Survival Guide for Yippie! Nation showed how Yippies! could survive and work for revolution, doing things for free or as cheap as possible. Some of the areas covered were clothes, drugs, housing, travel, and communications. The Youth International Party Line newsletter described how to get free phone calls, and in 1971 lost its political orientation though continued its leading role in the phreaking field under the name of Technical Assistance Program (TAP). The June 1972 issue of Ramparts (an alternative New Left publication) was confiscated for publishing a design for a phreaking box, and Ramparts soon ceased operation. The early phreaks used simple electronic boxes, or other devices, to alter voltages or generate tones that were able to control the phone network. One of the first inventions was the black box. It only required a switch and a 10k-ohm resistor, and allowed people to receive free calls by lowering the line voltage so it appeared that there was no conversation. The famous blue box produced a 2600hz tone which gave it control of a trunk, allowing a phreak to literally surf the phone network going from one switching station to another. A common trick was to use the box to hop around the world through a dozen locations to call the pay phone next to you. Phreaks not only wanted free phone calls (and they used their knowledge of the system to setup conference calls and build a phreak network), but also to explore the Ma Bell phone system. The ability to control switches and guide a phone call around the world is similar to the approach hackers would take on the Internet.

Phreaks had power, and some could even tap other peoples’ phone calls. In the mid-1970s AT&T was losing $30 million a year to phreaks, so in the 1980s they upgraded the system and started scanning for people playing tones on their lines and tracking them down. In 1983, the editors of TAP had an attempted arson on their house. In the mid eighties Phreaks started using computer programs called "war-dialers." These programs used the modem to call a range of phone numbers and keep a log of the results. Phreaks were looking for internal numbers used by the phone company. Hackers used them to find computers with dial-ups that they could try to break-in. The phone companies are now aware of these programs, and in some areas they are illegal. One easy phreak trick that still works in most areas is the red box. It fools a pay phone into thinking money was deposited by playing the same tone that the phone generates when you deposit of a nickel, dime or quarter.

The connection between phreaking and hacking grew as hackers wanted free, untraceable phone calls so that they could gain access into computer networks. Also as the phone system became digital, phreaks needed to learn how to hack into the computers that controlled the switches. Some individuals participated in both hacking and phreaking (Ex. Kevin Mitnick). Phrack, a hacking and phreaking electronic journal, is a prime example of the overlap between the two as it serves both communities.