A legally blind Massachusetts phone hacker admitted this week to federal computer intrusion and witness intimidation charges that could put him away for as long as 13 years.

Matthew Weigman, 18, pleaded guilty to two felonies before U.S. Magistrate Judge Paul D. Stickney in Dallas on Tuesday. Known in the telephone party-line scene as "Li’l Hacker," Weigman is widely considered one of the best phone hackers alive.

Relying on an ironclad memory and detailed knowledge of the phone system, the teenager is known for using social engineering to manipulate phone company workers and others into divulging confidential information, and into entering commands into computers and telephone switching equipment on his behalf. The FBI had been chasing Weigman since he was 15 years old, at times courting him as an informant. He was finally arrested last May, less than two months after celebrating his 18th birthday.

"I’ve been interested in phones since I’ve been about 8," Weigman said in a 2007 interview with Wired.com. "I talked to technicians when they came down here to do things on my phone."

"I will shoot." Listen to the Colorado Springs hostage hoax. Disconnecting a phone. Audio of Matthew Weigman at work.

In his plea deal with prosecutors, Weigman, who was born blind, admitted to a long criminal resume (.pdf). Among other things, he confessed to conspiring with other telephone hooligans who made hundreds of false calls to police that sent armed SWAT teams bursting into the homes of their party-line enemies.

In a new revelation, Weigman also admitted eavesdropping on customer service calls to Sprint, by dialing into a phone line used by Sprint supervisors to monitor their employees. Weigman parked on the spy line to overhear customers giving out their credit card numbers, which he memorized and passed to accomplices. Weigman and his friends used the numbers to purchase computers and other electronics.

The FBI began investigating Weigman after he staged a 2005 hostage hoax that sent police to the Colorado home of Richard Gasper, a TSA screener whose daughter refused phone sex with Weigman. When the FBI caught up with him more than a year later, cybercrime agent Allyn Lynd offered to make him a confidential informant, but called off the deal when AT&T discovered that Weigman was still manipulating the phone company.

Lynd later told a police detective that Weigman couldn’t stop hacking for more than 72 hours.

Weigman’s current troubles began in April, the month he reached adulthood. William Smith, a Verizon security investigator who’d been monitoring Weigman’s hacking and phoning in updates to the FBI, noticed that Weigman had used the name and identifying information of a Texas woman to turn on phone service at the East Boston apartment he shared with his mother and siblings.

When Smith disconnected the fraudulent account, Weigman turned it back on again.

Then Weigman began making harassing phone calls to Smith at his house.

To trick the security worker into picking up the phone, the hacker socially engineered phone company employees into sharing Smith’s billing records in near-real time, then used Caller ID spoofing to make Smith think someone was returning his own calls, according to court records.

"For example, Smith would call a travel agency to arrange for a flight," the FBI’s Lynd wrote in an affidavit. "A few minutes later, he would receive a phone call which appeared to be coming from the travel agency that he had just booked a flight through. When Smith answered the phone, Weigman would begin harassing him again."

Then on May 18, Weigman showed up at Smith’s New Hampshire home with his burly older brother. Smith felt intimidated and called the police, who arrested the hacker.

Weigman is set for sentencing on April 24. Under the terms of his plea agreement, he can withdraw his guilty plea if sentencing judge

Barbara M. G. Lynn gives him more than 13 years in prison.

(Hat tip: Dallas Observer)

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