The American who helped New Zealand teen hacker Owen Thor Walker mount an electronic attack on an internet server, has been sentenced to 90 days in prison and five years of probation.
US District Judge Michael Baylson sentenced Ryan Goldstein, 22, of Philadelphia, to 90 days in a halfway house followed by 180 days of house arrest, the Philadelphia Inquirer newspaper reported.
He ruled that the defendant, a university student, could serve his sentence during a leave of absence from school or during the summer.
Goldstein, who told the judge he had suffered a "computer addiction" since he was 12, was also fined $US30,000 ($NZ50,400) and prohibited from using a computer for five years except for work or school activities.
In February, Goldstein admitted to a single misdemeanour count of aiding and abetting Walker, an 18-year-old Whitianga hacker known as AKILL - in gaining unauthorised access to a University of Pennsylvania computer server by using a botnet.
The New Zealander was discharged without conviction at the High Court in Hamilton last July after admitting six cyber crime charges: both crown lawyer Ross Douch and defence lawyer Tony Balme told the court that police were interested in using Walker's skills on the right side of the law.
Justice Judith Potter ordered Walker to pay $9526 as his half share of the damage caused to the university computer and other costs of $5000, and ordered him to hand over his computer-related assets to police.
Walker was allegedly the mastermind of a "botnet" coding group and received just under $40,000 for his part in the attacks, which included a global adware scheme and the collapse of a computer server at the American university. The botnet was a network of home PCs that had been commandeered secretly by the hackers.
Goldstein and Walker used the university computer system as a staging ground for a 50,000-computer attack, said Assistant US Attorney Michael Levy. After Goldstein was arrested, he began cooperating with authorities, and his information led to Walker, who installed malicious software on 1.3 million computers worldwide, investigators said.
Mr Levy, who prosecutes about two computer-hacking cases a year, told the newspaper that Goldstein's cooperation "in the online hacking world was very useful" and led to at least seven other arrests.
Judge Baylson, however, said he felt some jail time was necessary for Goldstein because the FBI also found more than 1000 images of child pornography on his computer. Prosecutors had decided not to charge Goldstein with child pornography in return for his cooperation.
Later in the day, the judge commented on unfairness in sentencing when he sentenced another man, Derrick Williams, 32, of Philadelphia, to a heavy prison sentence the same day for the same crime.
"It seems very unfair," he said. "I want to note for the record that Mr Goldstein is white and Mr. Williams is African American and that adds to my discomfort," said Baylson. Both men had roughly 1000 images of child pornography on their computers, the judge said.
Both men were then sentenced, both men one right after the other, with Williams getting only two years, instead of the eight to 10 years recommended by sentencing guidelines.
Goldstein, who faced up to a year in prison, had been hoping for no prison time after his lawyer, Ronald Levine, said his client was "filled with constant guilt and remorse".
After the sentence was handed down, Goldstein was initially stoic, but tears streamed down his face as he left the courtroom.
