Two things come into that, really. One, when you're at the level of the News of the World, we're generally pretty experienced in this, so we knew what we needed to be looking for. But secondly, we would, as often as possible, liaise with the police and, as I said -- the great example being the dirty bomb plot, the woman selling the virginity, the woman selling the baby, et cetera, et cetera -- the police would make it very clear to us what they needed as evidence and how that evidence would need to be collected. So we would take that advice, together with our own experience -- and I think you've had Mazher Mahmood in here, whose proud record I think is that he has put away over 200 criminals, often in very dangerous circumstances. You know, you do that by making sure that (a) you know what you're doing and (b) that you liaise properly with the police.