I live in a fairly safe neighbourhood, but some people still use extra safety messages such as hanging up Beware of the dog signs by their doors. I've often wondered whether signs like these are actually effective at deterring criminals.
An article in the Athens-Banner Herald suggests that having a dog at your house, or at least pretending you do, might deter some would-be crims.
Over the weekend a lady in Georgia, USA, scared off a potential burglar by pretending to be a large dog. The woman saw through her window a man attempting to open her front door. The woman dropped to all fours by the door and imitated a dog. Exactly which dog-like characteristics she adopted has not been specified, but she must have been realistic as the man ran away.