Of course, that’s exactly what Saponas and his colleagues did, figuring out a few different ways of constructing tracking systems, from using Windows XP computers to mini ‘gumstix’ trackers that could be hidden in trees, a fence or elsewhere. A picture of the gumstix device is available at the report, which shows that it does need an antenna, meaning you’d have to hide it carefully or it could be noticed.

Nefarious uses for tracking people included people stalking on others, thieves casing home where Nike+iPod wearing owners live to discover when they had left home, and other bad sounding scenarios.

Interestingly, the system could be mapped to a GoogleMaps system, so people could be tracked in real time, and doubly interesting is the fact that Nike+iPod wearers don’t even need to be carrying their iPods with them as the Nike+iPod transmitter, which fits into the sole of compatible Nike shoes, is the transmission device.

While the transmitter can be turned off when not in use, this is something the user has to do manually, and few users bother to do this, or so it would seem.

As the transmitter has a unique identifier that can be picked up by any iPod (or other tracking device), users can be tracked at a range of 60 feet, which is a much greater distance than most Bluetooth devices.

Apple and Nike had no comment to make at the time of the reports hitting the Internet, and are no doubt deciding what their official reaction will be. Reaction from the public is mixed, with some not really worrying about the problem, while others consider it most Orwellian.