What does it mean to a young family when, shortly after moving into their dream home, they discover their new neighbor is a vengeful computer hacker bent on destroying their lives?

To Matt and Bethany Kostolnik of Blaine, it meant 707 days of living in fear for themselves and their small children until Barry Ardolf was jailed for hijacking their wireless router and using it to frame them with child porn and threats against Vice President Joe Biden.

"My husband and I had to explain to our young, innocent children way too early that there are evil people in the world -- and to never go in Barry Ardolf's yard," a sobbing Bethany Kostelnik told U.S. District Judge Donovan Frank before he sentenced Ardolf to 18 years in prison for a two-year campaign of terror against his neighbors.

Said Matt Kostolnik: "Until Ardolf was incarcerated, not a day went by that I didn't think about another attack."

Ardolf, 46, pleaded guilty last December to using his computer skills to first steal his neighbors' identities and then attempt to destroy their careers and reputations. Now, Ardolf will be locked up until well after the Kostolniks' children are grown.

It began in August 2008, just two days after the Kostolniks moved into their new house, when they called Blaine police to report that Ardolf had picked up their 4-year-old son and kissed him on the mouth. After that, Matt and Bethany Kostolnik said, all they wanted was to keep their distance from him. But Ardolf began exacting revenge.

In early 2009, he created e-mail accounts in Matt Kostolnik's name and used a password-cracking program to hack into the Kostolniks' wireless router. Posing as Kostolnik, he sent e-mails -- one containing sexually suggestive language, others containing images of child pornography -- to Matt Kostolnik's co-workers and boss.

After Ardolf sent threats to Vice President Joe Biden and others, investigators discovered Ardolf was hijacking the family's wireless service. A search of Ardolf's home in the summer of 2009 produced evidence taken from more than a dozen computers and dozens of computer storage devices, evidence that included detailed notes of e-mail addresses, passwords, photographs and text of e-mails that had been sent.

Investigators and Assistant U.S. Attorney Tim Rank confronted Ardolf with that evidence in the summer of 2010 and a plea deal was arranged. He would have served two to five years in prison. Ardolf, however, backed out of the deal, fired his attorney and hired another attorney to go to trial.

On Dec. 17, after two days of trial, Ardolf again decided to plead guilty. But, in May, Ardolf was back in court, trying to withdraw that plea. He even claimed that he was perhaps framed by the Kostolniks. Frank refused to let Ardolf withdraw his plea.

On Tuesday, the hacker whom Rank called "angry and arrogant" finally appeared to acknowledge his guilt, tearfully apologizing to the Kostolniks and his own family -- before complaining about jail food and the hardness of his bed.

Afterward, Rank was asked if spending nearly 20 years behind bars will change Ardolf.

"He may not be as arrogant," Rank said. "But he will probably be more angry."

James Walsh • 612-673-7428