tracking system for hunting them down the next time it happens. The matchbox-sized transponder device can be slipped into an item (above it's sitting inside a TomTom GPS unit) and then tracked via the CATSeye system. Device coordinates can be set to send at a regular interval, if the unit is moved (there's a motion sensor inside as well), or if it's taken outside of its assigned "geo-fence." The system mainly relies on GPS for tracking duties, but it can give GSM tower coordinates in a pinch, and a separate RF scanner can locate the unit with up to 1-inch accuracy. We're not quite sure how much the rest of the system costs, but the RF scanners range in price from $100 to $1000+. At those kind of prices the system is really best suited for keeping store inventory or for tracking items given to enterprise staff, but we still think the revenge angle is totally justifiable. Make sure to peep the read link for a video of the system in action.