An internet child abuser has been sentenced to jail following a lengthy case involving evidence gathered by illegal hacking.

66-year-old Ronald C Kline, a former senior judge from California, has been sentenced to 27 months in jail for possessing child pornography. Kline was initially brought to the attention of the authorities after his computer was infected by a Trojan horse planted by Canadian hacker Brad Willman.

Willman planted the Trojan horse, disguised as images of child abuse, on an internet newsgroup visited by pedophiles in 1999. The hacker, who used the handle Omni-Potent, broke into the PCs of those he infected, focusing on those he suspected of being involved in child abuse.

"Ronald Kline's conviction has brought to the end six years of legal arguments about whether evidence gathered by the Trojan horse was admissible," said Graham Cluley, senior technology consultant for Sophos. "Few will shed tears over Kline going to prison, but the case does raise interesting questions over whether illegal hacking and the distribution of malware can ever be justified. Some may worry that this case will be viewed as a green light for other hackers to infect computers with their malicious code."

It should be noted that malware has played its part in the successful conviction of other child abusers in the past.

In December 2005, a German man turned himself into the police after believing that an e-mail sent to him by the Sober worm was really a warning from the authorities investigating customers of illegal Web sites. In 2003, a judge said he was uncomfortable that the FBI had not told an anonymous hacker to stop his illegal activities because of information he was passing onto them.

KW