Well, I didn't envision this as a civil liberties debate. Instead, I thought it might be fun and edifying to brainstorm ways to accomplish what the French are requiring.

Toward that end, let's assume two cases. In one, only outgoing emergency calls need be allowed. In the second, incoming and outgoing emergency calls must be allowed.

My first suggestion is that it would be extremely difficult, if at all possible, to effectively block all calls in a given room without interfering with calls in adjacent rooms, if one is employing active electronic jamming techniques. This means that we must employ a faraday cage around the room we want to shield. Given the presence of a faraday cage, can we come up with any novel ways of discriminating the nature of the calls? Will we have no choice but to put in a repeater (with an antenna outside the faraday cage) which can monitor the placed call and forward only those sent to 911?

On a more viscerally satisfying level, what consequences could we impose on those calls placed to non-emergency numbers?

What about incoming calls? Is it possible to automatically intercept calls placed to cell phones inside the cage, but not to those outside the cage? And if so, how would one go about discerning a request to pick up a gallon of milk from the summons to meet your child and babysitter at the emergency room? How could one discriminate between a call from an adolescent friend wanting to discuss how the date is going, and one requesting the ObGyn report to work? Would there be a choice but to have a live person pick up the phone and ask? What would be the most effective and efficient ways to do this?