(Wired) -- A Minnesota hacker that prosecutors described as a "depraved criminal" was handed an 18-year prison term Tuesday for unleashing a vendetta of cyberterror that turned his neighbors' lives into a living nightmare.

Barry Ardolf, 46, repeatedly hacked into his next-door neighbors' Wi-Fi network in 2009, and used it to try and frame them for child pornography, sexual harassment, various kinds of professional misconduct and to send threatening e-mail to politicians, including Vice President Joe Biden.

His motive was to get back at his new neighbors after they told the police he'd kissed their 4-year-old son on the lips.

"Barry Ardolf has demonstrated by his conduct that he is a dangerous man. When he became angry at his neighbors, he vented his anger in a bizarre and calculated campaign of terror against them," prosecutor Timothy Rank said in a court filing. "And he did not wage this campaign in the light of day, but rather used his computer hacking skills to strike at his victims while hiding in the shadows.

"Over months and months, he inflicted unfathomable psychic damage, making the victims feel vulnerable in their own home, while avoiding detection."

Ardolf's attorney, Kevin O'Brien, said in a telephone interview that "it was a lengthy sentence for a first-time offender." The defendant also forfeited his house and computer gear.

Ardolf had no criminal record, but an investigation revealed that he'd also hijacked the Wi-Fi of other neighbors, and terrorized them as well.

A father of two, Ardolf had turned down a 2-year plea agreement last year to charges related to the Biden e-mail. After that, the authorities piled on more charges, including identity theft and two kiddie-porn accusations carrying lifetime sex-offender registration requirements. He pleaded guilty to them all last year.

The bizarre tale began in 2009 when Matt and Bethany Kostolnik moved in the house next door to Ardolf, who at the time was a Medronic computer technician living in the Minneapolis suburb of Blaine. On their first day at their new home, the Kostolnik's then-4-year-old son wandered near Ardolf's house. While carrying him back next door, Ardolf allegedly kissed the boy on the lips.

"We've just moved next door to a pedophile," Mrs. Kostolnik told her husband.

The couple reported Ardolf to the police, angering their creepy new neighbor. "I decided to 'get even' by launching computer attacks against him," Ardolf later wrote in a letter to the judge.

Rank, the prosecutor, put it not so mildly:

"It was apparently this incident which caused the defendant to begin a calculated campaign to terrorize his neighbors, doing whatever he could to destroy the careers and professional reputations of Matt and Bethany Kostolnik, to damage the Kostolniks' marriage, and to generally wreak havoc on their lives," he said.

Ardolf downloaded Wi-Fi hacking software and spent two weeks cracking the Kostolnik's WEP encryption. Then he used their own Wi-Fi network to create a fake MySpace page for the husband, where he posted a picture of a pubescent girl having sex with two young boys. Under the "about me" section, he wrote:

"I bet my coworker that since I'm a lawyer and a darn great one that I could get away with putting up porn on my site here. I bet that all I have to do is say that there is plausible deniability since anybody could have put this on my site. Like someone hacked my page and added porn without my knowledge. This is reasonable doubt. I'm a darn good lawyer and I can get away with doing anything!"

He then e-mailed the same child porn to one of the husband's co-workers, and sent flirtatious e-mail to women in Mr. Kostolnik's office. "You are such a fox," read one of the e-mails. He sent the message's through the husband's genuine e-mail account.

After the husband explained to his law office superiors that he had no idea what was happening, his bosses hired a law firm that examined his network and discovered that an "unknown" device had access to it. With Kostolnik's permission, they installed a packet sniffer on his network to try and get to the bottom of the incidents.

Then, in May 2009, the Secret Service showed up at Kostolnik's office to ask about several threatening e-mails sent from his Yahoo account, and traced to his IP address, that were addressed to Biden and other politicians. The subject line of one e-mail read: "This is a terrorist threat! Take this seriously."

"I swear to God I'm going to kill you!," part of the message to Biden said.

A forensics computer investigator working for Kostolnik's law firm examined the packet logs, and found the e-mail sessions sending the threats. In the data surrounding the threatening traffic, they found traffic containing Ardolf's name and Comcast account .

The FBI got a search warrant for Ardolf's house and computer, and found reams of evidence, including copies of data swiped from the Kostolniks' computer, and hacking manuals with titles such as Cracking WEP Using Backtrack: A Beginner's Guide; Tutorial: Simple WEP Crack Aircracking and Cracking WEP with BackTrack 3 -- Step-by-Step instructions. They also found handwritten notes laying out Ardolf's revenge plans, and a cache of postal mail that Ardolf had apparently stolen from the Kostolniks' mailbox and stashed under his bed.

"One of the manuals had Ardolf's handwriting on it and another had the unique identifying ID for the Kostolniks' router typed into it," Rank, the prosector, wrote.

Also discovered in Ardolf's possession was the pornographic image posted on MySpace and sent to the husband's co-worker, and evidence that he'd secretly staged a similar harassment campaign against a neighbor at Ardolf's previous home in Brooklyn Park, another Minneapolis suburb. Among other things, he sent that family a postal-mail message consisting of a one-page, color print-out of the family's "TurboTax" return with personally identifying information, in addition to several skull images.

"I told you about a year ago that you should be very afraid. I can destroy you at will, you sorry-ass excuse for a human," the letter said.

The Brooklyn Park family told the FBI they believed Ardolf was upset that their personal care attendants, who looked after their two disabled twin daughters, parked their car in front of his house.

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