More information in today's Washington Post article:

http://www.washingtonpost.com/local/scat...=pm_local_pop_b

"The outage immediately caught the attention of national security officials, who have heightened their scrutiny of vulnerabilities of the U.S. electricity grid after recent reports that nations such as China and Iran have infiltrated U.S. power company networks."

"...It disconnected the lines, power plants and generating units when it sensed a problem,” said Ray E. Dotter, a spokesman for PJM Interconnection, which coordinates the flow of electricity in 13 states and the District. Dotter said the fluctuation in the voltage probably left some in the D.C. area experiencing a power loss and others a power surge. “Those are protective measures. . . . It is easier to reset a system than replace.”