"Lost my phone, need numbers!" etc. I don't tend to join any serious groups on FB, ones that are supposedly there in order to try and get something to change. I do tend to join the more humorous ones like "The Very Hungry Caterpillar is Bulimic" and "Anatidaephobia - The fear, that some time, somewhere, some how, a duck is watching you". You can also find out a considerable amount about a person by what groups they have joined. Admittedly I only ever check facebook while travelling due to bordem. I have no real purpose for it.