We recently reported on the concern that the smart grid could be vulnerable to cyber-attacks, disrupting electricity service to millions of homes and businesses nationwide and posing a national-security risk.

Today, ABC's Good Morning America and The Wall Street Journal are reporting that cyber-hackers from China, Russia, and other countries have already infiltrated the U.S. electric grid and left behind software that could damage key infrastructure components of the national grid. The stories cite a former official with the Department of Homeland Security as a source. "There are intrusions, and they are growing. There were a lot last year," the official said.

Meanwhile, the Associated Press reported yesterday that the Pentagon has spent more than $100 million in dealing with cyber-attacks. e-mail | Twitter

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