Exploding the Phone: The Untold Story of the Teenagers and Outlaws Who Hacked Ma Bell, by Phil Lapsley, Grove Press, 431 pages, $26. 

During the Cold War, a shadowy group hacked its way into a system the technologist and entrepreneur Phil Lapsley calls “the world’s largest machine.” AT+T’s phone network was a vast enterprise of early cyberinfrastructure, combining hardware, information architecture, and an army of human experts. It was an irresistible lure to the phone phreaks, a group of curious folk who saw the government-protected monopoly’s empire as both a puzzle and a playground. Exploding the Phone, Lapsley’s delightful account of their adventures, sheds light on an underappreciated chapter in the history of technology. It also reveals the forerunners to the hacking subculture of today.

Exploding presents the stories of individual phreakers in chronological order, starting with the first people (AT+T employees excluded) who figured out how to poke into the phone company’s innards by generating unusual sounds. These included college students who built “blue boxes,” devices that emitted signals the phone network understood as legitimate commands. They also included several blind teenagers who could imitate those sounds by whistling. These proto-phreaks communicated in the early ’60s with free conference calls and other shared phone services, building a virtual community. Some created recordings and made them available via repurposed phone lines, and they sound like today’s Web or yesterday’s Usenet. “Most were comedy skits,” Lapsley writes, and “some were horoscope readings, others were political commentary and humor.”

Before they were labeled phreaks (that happened in 1971, via an Esquire article) these outside explorers built machines to imitate the phone system’s signals and to link two phones to make an ad hoc conference call; they methodically discovered codes for bouncing long-distance calls across multiple cities, reaching hidden exchanges. Meanwhile, as AT+T gradually realized that they were being invaded, the company slowly developed policy responses, including working with the FBI, tracking users, and ultimately recording millions of phone calls.

Many Americans, we see, saw the phone company as powerful, frustrating, sometimes terrifying, even fantastically megalomaniacal, a Leviathan anyone who’s seen the 1960s conspiracy comedy The President’s Analyst will recognize:

The contrast with the scrappy phreaks gives Lapsley’s book a David-and-Goliath flavor, an emotionally satisfying dynamic that gives life to his occasionally dry subjects. We can understand how outgunned the phreaks felt, then appreciate their boldness. The fact that so many phreaks were blind heightens the emotional investment. But Exploding the Phone doesn’t get trapped in the available underdog vs. evil empire clichés. AT+T’s enforcers sometimes appear as charming and clever, the phreaks’ doubles on the other side of a war. (One of the book’s revelations is that some phone workers were phreaks on the side.) Similarly, the phreaks are not always sympathetic. Nor are they always clever: In one particularly foolish mistake, the legendary phreak John “Cap’n Crunch” Draper, invites a warrantless FBI unit to search his belongings. The book’s characters are never cyphers for the larger struggle. (Draper got his nom de phreak by discovering that a toy whistle given away in Cap’n Crunch cereal made precisely the 2600 Hz tone needed to convince the phone system not to charge for a call.)

By the early 1970s, that struggle had escalated into a multi-agency campaign, with trials and prison time for the enemies of the phone company. Some of the more criminally inclined were killed in their line of work. Draper was the first to be jailed. After making a very visible presence of himself and pulling some impressive pranks—Crunch claimed to have called then-president Nixon in the White House, at which point he complained about a toilet paper shortfall—he served several years behind bars.

The book ends by guiding us through the transition from phone phreaking to computer hacking. Some explorers used early computers to increase their capacities to find more numbers and codes, while others took jobs with the post-breakup remains of the once-giant Bell. Two men who used to build and sell blue boxes—a couple of fellows named Steve Wozniak and Steve Jobs—founded a little company called Apple Computer. (Draper, meanwhile, created Apple’s first word processor.) Other phreaks moved into other passions as digital telephony gradually replaced the old analog systems, closing off the playground.

Nearly every chapter of the book takes time to patiently introduce another one of AT+T’s extraordinary technical achievements, either at the macro or micro scales. Lapsley introduces us to a shadow lexicon of terms: loop arounds, step-tandem switching, tandem stacking, open sleeve-lead conferences, inward operators, simultaneous seizures, to say nothing of blue boxes, black boxes, red boxes, and cheeseboxes. Yet this backgrounding never becomes overwhelming. Like a good teacher, Lapsley lays out small amounts of information at each encounter, carefully returning to those dollops in succeeding chapters. 

Why should we care about this combination of technical minutiae, eccentric characters, and byzantine organization? For one thing, the phreaking story gives us a first draft of the world of hacking. We see similar groups of determined youth spooking their elders, developing new identities, forming virtual communities. The phreaks demonstrate the hacker’s love of tinkering, for working through a puzzle for its own sake (plus the bragging rights). They use social engineering to winnow secrets and publish work through their own media – for the telephone it was the Yippie-spawned zine Youth International Party Line, later called TAP. They probe into the recesses of power, including the tools of a raging Cold War. (One FBI/AT+T/NSA investigation sought to determine if a phreaking method would let the proto-hackers scramble fighter planes.) The authorities fight and sometimes hire them.

History never repeats exactly, of course, and the differences between hackers and phreaks are instructive. We don’t associate hackers with blindness, for example. And while hackers have inspired a lot of media panic, phreaking enjoyed mostly serious and supportive commentary from media outlets—not just Esquire but Ramparts, The Wall Street Journal, and NPR show.

Phone phreaks also speak to non-hacking concerns. Their activities elicited several sorts of surveillance, both corporate and governmental, which in turn raised questions of when such entities could violate individual privacy—a debate that, needless to say, is still ongoing. The use of a virtual world to make up for offline limitations, be they visual impairment or social constriction, is one we’ve become accustomed to at a global scale. Perhaps as we see surveillance and and other forms of social control rise at the expense of personal freedom, the phone phreaks’ story will inspire some readers to probe other systems for weaknesses and mysteries. “If idle hands are the devil’s tools,” Lapsley informs us, “then a clever teenager with idle hands and a methodical personality is the devil’s munitions factory.”