Rain Noe links to Hop! The Following Suitcase, a concept by Rodrigo Garcia. This is an awesome concept, but Rain worries that this somewhat autonomous luggage might be a target for opportunistic thieves in an urban setting. He also mentions a taser as a possible security measure. While electric shocks are an apt punishment for a luggage thieves, perhaps, if the bag were to scream loudly if it were more than a few feet from its owner might be just as effective. In fact, if the blood curdling screaming were to increase in volume the farther the suitcase was taken, a thief would probably drop it quite quickly.
The owner would just need to remember to disable the scream alarm before gate checking the bag.