Ronald Kline, a former judge at Orange County Superior Court has been sentenced to 27 months in jail for possession of child pornography.

Kline was arrested in 2001 after he was reported to authorities by a vigilante hacker who had been monitoring Kline's computer without his knowledge.

Kline admitted at the time that he had stored more than 100 sexually explicit images of under-aged boys on his computer.

The hacker, Brad Willman from Canada, was 20 years old at the time. In a 2002 interview with the Ottowa Citizen, William admitted to hacking into 3,000 computers using a Trojan hidden in an image that promised a pornographic image of a child.

His actions have since exposed child predators across Canada, the US and Russia.

Kline's defence attorney had argued that the evidence gathered from the judge's computer was inadmissible because it had been stolen.

After initial victories, the defence was overturned in 2004, followed by a guilty plea in December 2005.