To my knowledge, RFID is not being used to track paroled convicts or pedophiles. RFID is a short-range technology. Active tags can be read from perhaps a thousand feet away, so in order to track people, you would need to install a network of interrogators on almost every single street corner. Clearly, this would not be feasible.
GPS is better for such an application, in that it can locate individuals anywhere, provided they are outside. Given that a GPS transmitter can determine someone has entered or left a house, this is usually sufficient. It could be possible to combine RFID and GPS in order to indicate where someone is located within their home, if that were required for some reason.
—Mark Roberti, Editor, RFID Journal
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