I didn't mean to scare the Nike+ iPod toters out there but an interesting article on Wired explores the vulnerabilities of the high-tech shoe accessory. I first introduced you to the Nike+ system back in May, ahead of its July launch date. Back then it was a neat idea to be able to track your running status and pace all within the friendly iPod experience and interface. The Nike+ RFID device in the sole of your shoe presents a not-so-friendly, nefarious use.
Additionally, the sensor will reveal its unique ID to any Nike+ iPod receiver. With a quick hardware hack that Kohno said "any high school student could do in the garage," the researchers hooked a Nike+ iPod receiver up to a Linux-based "gumstix" -- a tiny, 79 computer that could easily be hidden in door frames, in trees next to jogging trails or in a pocket. Source: Wired
Ideally, the Nike+ RFID device should be unique and only communicate to the bundled iPod receiver instead of any iPod receiver. Also, since the RFID device was designed to be used wirelessly several feet from the iPod, engineers had to beef up its transmission power and make it active instead of passive. I wasn't able to find any specification sheets to determine the power of the Nike+'s RFID transmission, but considering it has its own battery I would say it is roughly 50x stronger than the passive RFID tag found in your Exxon Mobil Speedpass (most RFID tags utilize the radio waves of the receiver for power).
The moral of today's story is that people can find out where you've been by tapping into the potential of your Nike+'s RFID tag so you should just be extra careful if you like taking jogs in the high-tech ghetto. While Wired's article is plausible, I find it very rare that such a hypothetical situation as below would ever occur.
In their report, the researchers detail a scenario in which a stalker who wants to know when his ex-girlfriend is at home taps into her Nike+ iPod system. He simply hides the gumstix device next to her door, and it registers her presence as she passes by in her Nike shoes. If he adds a small "wifistix" antenna to the device, it can transmit this information to any nearby Wi-Fi access point and alert him to her presence via SMS or by plotting her location on Google Maps.