Thursday’s massive power outage across parts of Arizona and southern California serves as a reminder of the vulnerabilities in the nation’s power infrastructure. The outage appears to have been caused by human error, but that fact is unlikely to comfort the growing number of people concerned about blackouts that could be triggered by cyber attacks. In 2008, a fire in a substation near Miami triggered a cascading blackout across a large swath of Florida, leaving three million people without power for hours. In 2003, a similar blackout in the northeast affected 15 million people in New York, Connecticut and even parts of Canada and the Midwest.”]