They’re called “phreakers,” and they can do with a phone what hackers can do with computers. Few were more skilled—or more feared—than Matt Weigman, a blind teenager from East Boston. Using his heightened senses, he made himself untouchable. What he lacked, the FBI says, was the good sense to know when to hang up.

Until the 1950s, the bulk of the U.S. phone system operated manually. Calls were placed via live operators connecting the right wires to the right jacks, forming one long connection by hand. Over time, with the advent of electronic switches, networks were automated, with calls relayed through a system of giant call centers and then on to the intended recipient. A price of the efficiency of these vast networks was the loss of human gatekeepers. There were loopholes and glitches in the new system, and no one to guard them.
The phreaker scene first sprang up in the early 1960s, in the hotbeds of technological innovation—places like Cambridge and the Pacific Northwest. “The personal computer didn’t exist then,” says Phil Lapsley, who is at work on a book on the history of phreaking. “And the closest thing you had to a computer or a network was the telephone system.”

Tech luminaries Steve Jobs and Steve Wozniak, cofounders of Apple, were part of the early subculture. The pair jury-rigged a device that allowed them to make free long-distance calls. In a move later cemented in phreaking lore, Wozniak once employed it to place a call to the Vatican, during which he impersonated Henry Kissinger and was nearly connected with the pontiff himself.

“We wanted to learn about the network,” says Bill Acker, a top phreaker of the time. “It was this big toy box.” Phreaking in its purest form was an impish pastime with discovery as the goal. “Phone phreaking is a relatively benign activity done by people looking to find out new things, people who want to play games and learn along the way,” says Chris Bernay (a phreaking alias), a comrade of Acker’s.

Both Bernay and Acker, as it happens, are also blind. Indeed, the scene in the 1970s was full of blind phreakers. Among the most famous was Joybubbles, the legal name of a man formerly known as Joe Engressia. A bona fide genius, he was seven years old when he discovered that whistling into the phone at specific frequencies could trigger certain telephonic switches. Before long he was whistling for free calls. His exploits, though, were short-lived: In 1971 he was caught by the FBI and charged with malicious mischief, and from then on the 22-year-old resolved to keep the tinkering aboveboard.

Phreakers who are so inclined can cause a surprising amount of harm with a phone. Consider the three blind brothers in Israel who managed to exploit an inactive feature within the Israeli army’s telephone system to build their own phone company. Charging their customers and then using the hacked phone system to place calls for free, the brothers and their associates pocketed $2 million before they were nabbed in 1999. Just last August, another phreaker wormed into the telephone network of the Federal Emergency Management Agency (which is part of the Department of Homeland Security) by breaking into the voice-mail system. Once in, the hacker made $12,000 worth of calls to the Middle East and Asia.

Even for today’s phreakers, there’s still a thrill in merely getting access to something not intended for them. Something like the machines near the giant fish tanks at Kelly’s Roast Beef restaurants, which monitor water temperature and noise levels and offer a menu of reports and 15-second live audio feeds through a phone system accessible to Kelly’s employees—and to the curious phreakers who dial in as well. Phreakers make such finds by scanning—dialing numbers sequentially until they stumble onto something interesting. It takes time and patience to do this. They have to work as a team. But they can uncover oddities like inactive intercept recordings from the phone companies (“We’re sorry, but due to a mudslide in the area, your call cannot be completed”). The rewards can be as simple as that. A new find, some bit of uncharted territory.

Weigman knew this history well and revered the pioneers of the practice; he even spoke to Joybubbles on occasion until his death in 2007. He picked things up quickly, and as he got into phreaking, his forays were harmless enough. He could remember long sequences of tones—10, 15, 20 at a time—after just one listen, which could be helpful if you overhear the tones for someone’s voice-mail password, and then maybe want to log in to that person’s account. Probing their systems for soft spots, he learned the phone companies inside and out, and held a mental Rolodex of hundreds of numbers and names. He started memorizing the industry jargon. Then he began putting it to use by calling internal phone company numbers and using the right buzzwords to get the operators to hook up free service for him. By dropping the correct lingo on the operators, he could also manipulate other people’s service. Among the phreakers, this is referred to as social engineering. The FBI calls it pretexting. Everyone else knows it as conning.