Stuxnet malware is 'weapon' out to destroy ... Iran's Bushehr nuclear plant?, by Mark Clayton. The Christian Science Monitor, September 21, 2010.
The Stuxnet malware has infiltrated industrial computer systems worldwide. Now, cyber security sleuths say it's a search-and-destroy weapon meant to hit a single target. One expert suggests it may be after Iran's Bushehr nuclear power plant.
By August, researchers had found something more disturbing: Stuxnet appeared to be able to take control of the automated factory control systems it had infected – and do whatever it was programmed to do with them. That was mischievous and dangerous.

But it gets worse. Since reverse engineering chunks of Stuxnet's massive code, senior US cyber security experts confirm what Mr. Langner, the German researcher, told the Monitor: Stuxnet is essentially a precision, military-grade cyber missile deployed early last year to seek out and destroy one real-world target of high importance – a target still unknown.

"Stuxnet is a 100-percent-directed cyber attack aimed at destroying an industrial process in the physical world," says Langner, who last week became the first to publicly detail Stuxnet's destructive purpose and its authors' malicious intent. "This is not about espionage, as some have said. This is a 100 percent sabotage attack."
http://www.langner.com/en/

This is pretty amazing.