"High-voltage transmission lines strung from support towers sprawl for thousands of miles across the United States and form the backbone of the nation's electric power grid. The grid carries power from generating sources to industrial complexes, urban areas and rural communities across America. On its march from power generators to consumers much of the high-voltage transmission corridor passes through remote areas where security is scant or not available. Authorities recognize that our power grid is vulnerable to terrorist attacks, vandalism and extreme natural conditions including weather, fire and seismic activity. These conditions can bring lines and towers down and disrupt service to wide areas of the country. Until recently, there was no cost-effective way to comprehensively monitor the grid, optimize performance and protect it from catastrophic failures."
Idaho National Laboratory: http://www.inl.gov