Quoted from PinChili:
I've often considered whether putting a GPS unit in each of my games would be a wise investment.
amazon.com link »
Not a bad idea but several problems with that. That unit only has 240 hours of stand-by battery. You could plug it in to the service outlet but you would have to find out quickly about the theft and react just as fast. Anyone who is stealing a pinball is probably going to be somewhat knowledgeable and drill out the lock. They will likely see the strange cord in there.
Sorry to hear about the game though. That's rough, quite a bit of this happening lately