"The last few years have seen the threat of a crippling cyber-attack against the U.S. electric grid increase significantly. Secretary of Defense Leon Panetta identified a 'cyber-attack perpetrated by nation states or extremist groups' as capable of being 'as destructive as the terrorist attack on 9/11.' A five-year old National Academy of Sciences report declassified and released in November 2012 found that physical damage by terrorists to large transformers could disrupt power to large regions of the country and could take months to repair, and that 'such an attack could be carried out by knowledgeable attackers with little risk of detection or interdiction.' On May 16, 2013, the Department of Homeland Security testified that in 2012, it had processed 68% more cyber-incidents involving Federal agencies, critical infrastructure, and other select industrial entities than in 2011. It also recently warned industry of a heightened risk of cyber-attack, and reportedly noted increased cyber-activity that seemed to be based in the Middle East, including Iran. Current efforts to protect the nation's electric grid from cyber-attack are comprised of voluntary actions recommended by the North American Electric Reliability Corporation (NERC), an industry organization, combined with mandatory reliability standards that are developed through NERC's protracted, consensus-based process. Additionally, an electric utility or grid-related entity may take action on its own initiative. In light of the increasing threat of cyber-attack, numerous security experts have called on Congress to provide a federal entity with the necessary authority to ensure that the grid is protected from potential cyber-attacks and geomagnetic storms. Despite these calls for action, Congress has not provided any governmental entity with that necessary authority."
United States House of Representatives: http://www.house.gov/