So critical computer networks get an on/off switch tied into some central location like the homeland security office which then gets hacked shutting down said critical computer networks while the individual network admins find ways of circumventing the master switch so they can get back online. Wonderful idea.
"The source said that one primary concern was the electrical grid, and what would happen if it were attacked from a broadband connection."
Uhh maybe the broadband connection attacking it would go down along with the substation its attacking? Or are they worried about some kid accidentally plugging his ethernet line into an electrical outlet, spreading a worm to toasters worldwide?