RFID

Radio Frequency Identification (RFID) is, basically, a nifty little trick whereby a radio transceiver is powered by the signal it is supposed to respond to.

It generally takes the form of a small, very low power computer chip that is designed to capture and interpret a signal from a base station and issue a response to the message sent; it's widely used in identification cards, public transportation fare collection, pet and livestock identification, and inventory control.

Although it remains a bit too expensive to replace bar codes for retail businesses, it's cheap enough that experimenter kits are available from most of the big hobby electronics sellers for about US$50. And it scares the living crap out of the tinfoil hat crowd.

Christian
US Christian fundamentalists, obsessed as they are with the Book of Revelation, have been claiming for years that this or that identity scheme is the Mark of the Beast, and since bar codes have become far too ubiquitous without any obvious role in universal persecution, RFID (especially in the form of glass-encased implantable chips, the kind used for the above-mentioned pet-tracking) is the latest of their bugaboos.

Others are less concerned about its role in a future judgement and more the possibility of forced implantation for the purpose of tracking people; that particular idea has figured into some of the conspiracies surrounding Obamacare, as well as enabling the sale of "RFID-blocking" clothing and carrying gear.

Public perceptions of RFID may be colored by its frequent use in fiction, including shows like The Blacklist and Babylon 5, where fictionalized RFID tags and implants usually have substantially greater range than the distances typical of real-world use; in reality, tracking someone generally requires a powered transmitter, something most mobile phones can do (primarily for the convenience of emergency services, although mobile phone tracking is sometimes used for surveillance purposes), but which RFID gear simply isn't capable of doing.

RFID (and its close active-circuit relative, near-field communication) plays a role as well in the more realistic aspects of transhumanism; Professor Kevin Warwick of the UK's University of Reading was among the first of a number of people to get an RFID tag implanted as part of a series of ongoing experiments in human/computer interfacing, and a number of smartphones now have NFC capability to do many of the same things as RFID cards can do.

Conspiracy theorists have a tendency to crying out MARK OF THE BEAST over the tiniest news reports even remotely involving microchips. and making large documentaries about their version of their theory. . One state even banned RFID chips solely because they were worried that they were the Mark of the Beast.

Note that even though Religious nutters talk about how we're about to be chipped with the Mark of the Beast, they seem to be failing to realize that states are banning forced RFID tagging. Of course to these people the possibility that sex offenders might need to be implanted in the future proves RFID is the mark. Sigh…. One has to wonder if these people even read their Bible.

Non-Christian
Other conspiracy theorists sometimes merely suggest that the US government will use RFID implants/IDS/passports to track citizens wherever they go to fit with whatever particular variation of the New World Order wants.