i too was emailed with this. i have since done it, better safe than sorry. not only because of the london attacks though. my father was in a bad accident 2 years ago (he passed on from the injuries). luckily he had a list of phone #s in his wallet that the police used to contact the family. however, it wasn't specific enough. we ended up hearing about his crash from a friend of the family whom the police called first. i think it is just common sense to do this, and a good idea. any little bit of info. helps.