Didn't see any threads about this.. A worm called Stuxnet had infected some computers at a power plant that is capable of rewriting PLC's and hiding it. The worm was apparently made specifically for this and people are saying that the only way a worm like this could come to exist would be via state sponsored cyber terrorism.
http://en.wikipedia.org/wiki/Stuxnet
http://www.bbc.co.uk/news/technology-11420226
http://www.computerworld.com/s/artic...t_worm_spread_
Who done it?