GPS tracking units that you can fit to your car to track where your kids are taking it (or *cough* other purposes) have been around for awhile now. It's interesting to see that recently the sorts of places that'll sell you card skimmers and RFID cloners have started selling miniature GPS jammers that plug into cigarette-lighter sockets on cars (general-purposes ones using internal batteries have been around for awhile). In other words these are specifically designed to stop cars from being tracked.
(Some of the more sophisticated trackers will fall back to 3G GSM-based tracking via UMTS modems if they lose the GPS signal, it'll be interested to see how long it takes before the jammers are updated to deal with 3G signals as well, hopefully while leaving 2G intact for phonecalls). Peter. --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majord...@metzdowd.com