"An aggressor nation or extremist group could use these kinds of
cyber tools to gain control of critical switches. They could derail
passenger trains, or even more dangerous, derail passenger trains
loaded with lethal chemicals. They could contaminate the water
supply in major cities, or shut down the power grid across large
parts of the country."
US Defense Secretary Leon E. Panetta
Panetta Warns of Dire Threat of Cyberattack on U.S.
New York Times October 11, 2012
Digital News Digest