That's the first I've heard of that. How would the people in Virginia use their phones to report the cream colored van's location if they shutdown the cellular network?
I wonder if it wouldn't be impossible to set the cell nodes to only accept calls to 911?
Of course, it would scare the heck out of families trying to contact members at large in the shooting area, but, it would also help to prevent communication between hypothetical terrorist groups on their sniper mission.