http://www.youtube.com/watch?v=1lF3eywqD-I

Former CIA Director James Woolsey says a cyber attack on the grid is entirely possible, so does U.S. Defense Secretary Leon Panetta (like, duhhhhhhh).

No government agency has authority over grid security!

Talks about how a hacker could leave malware in a system and have it be triggered at a later time.

A lot of government buildings and homes will be OK for 3 or 4 days because they have generators (solar and wind people would do MUCH better!) Beyond that you are back in primitive circumstances.