[briandear]

Viruses that take out nuclear weapons facilities from countries such as Iran and North Korea seen like a far better alternative than using traditional weapons. I can't think of any case where civilians were killed by a computer virus.

[freehunter]

Not yet, but it is still completely possible. Stuxnet was designed to cause physical damage to sensitive equipment. Imagine if a virus overloaded a power system. People could be injured by damaged transformers, people could be killed by failing electronics (anything from streetlights/stoplights to failing medical equipment). Iranian nuclear employees could have been injured or killed by the failing centrifuges.

Anything that relies on inter-networked controller systems has potential to be attacked by a virus, and many of them have potential to be destructive to human life.