Police say he started his criminal activities at the tender age of 16.

"I knew it was illegal," he says. "I just didn't think it was that bad. Like, just a bit of fun, as you do when you're a teenager."

Walker estimates that he made $40,000 (US$21,500) from his illegal operation, most of which was spent in true geek fashion. "I spent it on toys like a new computer, X-Box, games, buying pizzas for friends," he says.

His parents, also interviewed in the TV3 piece, knew they had a nerdy kid. But on the day of Walker's bust they didn't think they were raising a criminal. His stepfather, Bill Whyte, remembers the arrest: "I initially thought porn," he says, thinking his son was "too straight" for cybercrime.

Walker may have received a light sentence, but even New Zealand police didn't think he should go to jail. "The worst thing that society could have done was put him in jail, where his mind would have been corrupted," Maarten Kleintjes, head of e-crime with New Zealand Police, says in the interview.