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.

At about 1 a.m. on June 12, 2006, a 60-year-old truck driver named Jim Proulx walked out of his Alvarado, Texas, trailer home and into the sights of assault rifles. The guns were held by SWAT team officers responding to a dire 9-1-1 call from Proulx’s phone number. A caller who’d identified himself as Proulx said he was on hallucinogens, that he had an AK-47 and had just killed his wife. He said he was holding his daughter hostage, and would kill her, too, if he wasn’t given $50,000 and transport to Mexico. He also said that he was looking to kill some police officers.

It wasn’t the sort of situation the people of Alvarado—with a population of 4,000 and zero murders in the previous six years—were used to handling. If the cops were high-strung, it was understandable. They had no way of knowing that Proulx hadn’t made the call.

Proulx had no way of knowing what was happening, either, no way of realizing that as he walked out the door there were several different ways he could die. Maybe Proulx, only a few months removed from open-heart surgery, would find the commotion too much for his weakened heart. Perhaps the police would mistake an unfortunately timed reflection off his watch for the glint of a gun barrel. Considering all the threatening calls he’d been receiving over the past few weeks, it was a wonder Proulx hadn’t armed himself before heading outside.

But Proulx had no weapon, and when the cops got inside his trailer, there was no dead wife, no hostage daughter, nothing. The 9-1-1 call had come from the Seattle area, placed by a man who’d used the Internet phone service Skype and a computer program to make it look as if the call was coming from Proulx’s phone. And those menacing calls that had been ringing in for weeks, goading Proulx to a showdown: At least one of them had come from East Boston, from the bedroom of a 16-year-old blind kid named Matt Weigman.

It had started as a game, an absurd bit of one-upmanship orchestrated within an underground culture composed of tech geeks from across the country who congregated on telephone chat lines. Yet by the time the mischief reached its dark crescendo and Jim Proulx was set up for a shootout on his front steps, the whole thing had spiraled into something far more sinister. Nobody knew this better than Weigman, who’s scheduled to stand trial this month on federal charges that could earn him more than 20 years in prison. (Weigman has pleaded not guilty to the charges against him; neither he nor his lawyer would comment for this story.) Today, as he sits in a jail cell in Texas, Weigman is just another inmate, another head to count before lights-out. But in the world he made with his phone, the boy who called himself Li’l Hacker was a king.

It was the party line that gave birth to the game, and the party line was everything to Matt Weigman. A decidedly low-tech form of social networking, party lines are essentially toll-free chat rooms, open to anybody with a dial tone. Before World War II, when many homes in a community shared a single phone line, more than a dozen callers could join the conversation on the so-called party line. These days, callers dial in and then shuffle through “rooms” of live conversations.

The party lines that Weigman frequented were populated not by the purring coeds of late-night TV ads, but rather by lonesome souls searching to fill some social void. Like a junior high cafeteria, the party-line scene was replete with social hierarchies and unnecessary conflicts. It was a place for techie teens, for overwrought boys looking for sex and settling for drama.

To Weigman, it was a perfect social outlet. He was born blind, his optic nerve atrophied and damaged. During his early childhood, he was paired with an advocate who taught him how to crawl and later how to read Braille. There was briefly hope that his eyes might flicker to life: When he was four, Weigman’s mother turned on the lights of the Christmas tree, and Matt told her he could see them. His mother, knowing her son had already developed an uncanny sense of hearing, thought he’d merely heard the click of the switch and thus made the connection. No, Matt said. He saw the lights. But while Weigman would achieve some ability to discern light, the world never came into view for him. He grew up self-conscious about his impairment, aware of his limitations and embarrassed by his eyes; he knew how their tendency to roll rapidly and involuntarily (likely due to nystagmus, a condition common in those with optic nerve damage) freaked people out. He didn’t go out much.

When he was 11, Weigman discovered the party lines. Within a couple of years, friends say, he was spending days at a time dialed into them. Along with offering entertainment and a sense of community, the hobby appealed to his interest in the technological without requiring facility with a computer—something he had limited use for, given his lack of sight—and that rewarded his extraordinary sense of hearing and the supercharged auditory memory he’d also developed. It wasn’t just the talking on the phone but also discovering how the phone system itself worked that excited him. Among the party-line regulars, he found a subculture of tinkerers, enthusiasts known as phreakers, who probe and scan telephone networks, developing hidden tricks and looking for vulnerabilities to exploit. Among the phreakers, Weigman was soon considered one of the best.