Can Russia turn off our lights?

One hot day in August 2003, much of the northeastern United States and the Canadian province of Ontario suffered the biggest blackout North America has ever seen. A sudden power surge crippled hundreds of power plants and knocked out service to some 50 million people — darkening homes and businesses, halting trains and subway cars, snarling airline service and trapping people in elevators. Most of the affected places didn’t get the lights back on for two days.