I assumed that, like all other phones I've ever had, when the iPhone is locked the only thing you can do with it is make an emergency call - 999, 112 or whatever. But no, press 'Emergency Call' and you can then proceed to dial whoever you like and then have a nice long chat with them. What's the point in having a phone that locks but then allows someone to pick it up and call their grandmother who's on holiday in New Zealand? All the time running-up a massive bill that you have to pay. It's ridiculous!