RFID Tags in Washington Licenses Raise Questions
They're in your car if you cross the Tacoma Narrows Bridge using the electronic toll option and in your driver's license if you sign up for new "enhanced" Washington state licenses and ID cards that can be used to travel to Canada. They are tiny radio-frequency ID (RFID) tags the size of a computer chip used to hold and transmit information from a distance. Their use is growing to encompass not only clothing tags and payment cards, but also many transportation systems.
Privacy concerns attached to RFID tags, Seattle Times, July 19, 2007.