A fascinating article explaining how a nasty computer virus set Iran's nuke ambitions back for hopefully a long time: http://www.foxnews.com/scitech/2010/...ear-ambitions/
The construction of the worm was so advanced, it was “like the arrival of an F-35 into a World War I battlefield,” says Ralph Langner, the computer expert who was the first to sound the alarm about Stuxnet. Others have called it the first “weaponized” computer virus.--Masking itself from the plant's security and other systems, the worm then ordered the centrifuges to rotate extremely fast, and then to slow down precipitously. This damaged the converter, the centrifuges and the bearings, and it corrupted the uranium in the tubes. It also left Iranian nuclear engineers wondering what was wrong, as computer checks showed no malfunctions in the operating system.
Estimates are that this went on for more than a year, leaving the Iranian program in chaos. And as it did, the worm grew and adapted throughout the system. As new worms entered the system, they would meet and adapt and become increasingly sophisticated.