Can illegal hacking be justified?

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. He planted the Trojan horse, disguised as images of child abuse, on an internet newsgroup visited by pedophiles in 1999. The hacker (with alias Omni-Potent) broke into the pc's of those he infected, focusing on those he suspected of being involved in child abuse.
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. I am really worried that this case will be viewed as a green light for other hackers to infect computers with their malicious code. It's very difficult to draw the line here and this will remain very difficult in the future but there are other legal ways to gain the information you need and I know what I am talking about as my wife is a police-officer and teacher at the police academy. There are always legal methods like forensic investigation done by the Computer Crime Unit to obtain the necessary information. This way (the hacker's way) is at least completely unethical.
You can find more about the Virtual Global Taskforce - a group of police forces working around the world together to find online child abuse at http://www.virtualglobaltaskforce.com and you can always contact the Belgian FCCU at http://www.ecops.be to report it.