[From Wikipedia]: Radio-frequency identification (RFID) is a technology that uses communication via radio waves to exchange data between a reader and an electronic tag attached to an object, for the purpose of identification and tracking. Some tags can be read from several meters away and beyond the line of sight of the reader. The application of bulk reading enables an almost parallel reading of tags.
Radio-frequency identification involves interrogators (also known as readers), and tags (also known as labels).
Most RFID tags contain at least two parts. One is an integrated circuit for storing and processing information, modulating and demodulating a radio-frequency (RF) signal, and other specialized functions. The other is an antenna for receiving and transmitting the signal.
There are three types of RFID tags: passive RFID tags, which have no power source and require an external electromagnetic field to initiate a signal transmission, active RFID tags, which contain a battery and can transmit signals once an external source ('Interrogator') has been successfully identified, and battery assisted passive (BAP) RFID tags, which require an external source to wake up but have significant higher forward link capability providing greater range.
RFID Privacy Issues and News - http://www.spychips.com/
Radio Frequency Identification (RFID) - [Electronic Frontier Foundation] - Libraries, schools, the government, and private sector businesses are adopting radio frequency identification tags, or RFIDs ó a technology that can be used to pinpoint the physical location of whatever item the tags are embedded in. While RFIDs are a convenient way to track items, they are also a convenient way to do something far less benign: track people and their activities through their belongings. EFF is working to prevent the embrace of this technology from eroding privacy and freedom. - http://w2.eff.org/privacy/Surveillance/RFID/
RFID tags: Big Brother in small packages - (January 13, 2003 -CNET) - Could we be constantly tracked through our clothes, shoes or even our cash in the future?
I'm not talking about having a microchip surgically implanted beneath your skin, which is what Applied Digital Systems of Palm Beach, Fla., would like to do. Nor am I talking about John Poindexter's creepy Total Information Awareness spy-veillance system, which I wrote about last week.
Instead, in the future, we could be tracked because we'll be wearing, eating and carrying objects that are carefully designed to do so.
The generic name for this technology is RFID, which stands for radio frequency identification. RFID tags are miniscule microchips, which already have shrunk to half the size of a grain of sand. They listen for a radio query and respond by transmitting their unique ID code. Most RFID tags have no batteries: They use the power from the initial radio signal to transmit their response.