Some Voluntarily Implant RFID Tags Under Their Skin
About 30 people around the world have independently inserted radio frequency identification chips, known as RFID tags, into their bodies, according to Web-based forums devoted to what participants call getting tagged. The tiny silicone chips, which for years have been safely implanted in pets and livestock to identify their owners, come with an encoded string of numbers. (Some chips have a small amount of memory that can be updated.) They are read by a scanner two to four inches away, much like a bar code except the chips don't need to be visible to be read.
High Tech, Under the Skin, New York Times, February 2, 2006.
