NSA chief says U.S. infrastructure highly vulnerable to cyber attack

US critical infrastructure - which ranges from telecommunications to water to energy supplies - is not well prepared to handle a destructive cyberattack, the top U.S. general in charge of cybersecurity said.

"On a scale of one to 10, with 10 being strongly defended, our critical infrastructure's preparedness to withstand a destructive cyberattack is about a three based on my experience," Alexander, also in charge of the U.S. military's Cyber Command, wrote in the statement prepared for the Senate Appropriations Committee for a hearing on cybersecurity. Alexander said it was vital to have a strong Defense Department role in cyberspace in light of what he called real and growing threats.