Pretty much everything else runs on the net, why not the phones too?
That makes the net a single point of failure. I hope yesterday's attacks suggested something to the powers that be. We have dumb phones, but also have a tablet, which doesn't handle phone calls but which can handle Skype. Provided the net is up. At least mobile phones aren't run over the net yet.
All the wonderful ideas: pay your bills with smartphones, pay bus fare with smartphones, use smartphone for ID, use smartphone for RFID key entry--do the inventors have any notion how fragile their system is?