FoeBuD, (http://www.rfidbuzz.com/wiki/Actors/FoeBuD) a German group of RFID and privary activists has presented the alpha version of their DataPrivatizer. The DataPrivatizer can detect RFID chips and scanners.
http://www.wizards-of-os.org/index.php?1629&L=3
Earlier this year FoeBuD activities have forced the retailer giant METRO to call back RFID enabled loyalty cards.
http://www.rfidbuzz.com/news/2004/metro_calls_back_payback_with_rfid.html
Source: heise(in German).
Rainer Wasserfuhr
RFIDbuzz.com, 13. Juni 2004
Original: http://www.rfidbuzz.com/news/2004/foebud_presents_rfiddataprivatizer.html