Stranger Danger .....

"The one horrifying story I have that causes ME caution, was long ago, and it probably doesn't apply here, but I'll mention it: a childhood friend of mine went on a trip with a group of new friends he met. They turned out to be a cult of some sort, who were seeking a sacrificial victim. They killed him, cut him into pieces, and left him strewn around the countryside. Up until they did that, they seemed very nice and friendly. Like I said, though entirely true, this is an extreme example, and probably the sort of thing your friends and family are concerned about."