Several months ago, there was this woman in a nearby town (Bixby, OK) who was selling a pool table (or something like that ... the details escape me), and she allowed a prospective buyer into her house. He kidnapped her, and soon after killed her, beginning a killing spree that stretched through three or four states. I think they eventually caught him in Mississippi. He killed two or three people besides that woman between here and there. So no, I don't think it's horrible that you think about that sort of thing when you go to make transactions with a stranger. A little paranoia can be a healthy thing.