German retail and wholesale giant Metro has abandoned a high profile trial of smart chip RFID technology in its customer loyalty cards.

The decision comes in the wake of an outcry from privacy groups and just before a planned protest by a German digital rights group called Foebug.

Metro said it would exchange cards that have already been issued for conventional cards without chips.

The German group explained that their actions were a bid to dispel any doubts about RFID even if they are chiefly of an emotional origin, irrespective of the legality of the cards.