The highlights of the wiki for those not reading it:
The laboratory found that the card contained only a standard radio frequency security tag of the type used in stores to prevent shoplifting.
The card could not be programmed, had no memory, no microprocessor and no form of information could be stored on it.
Despite the high cost of the devices, the cards were worth only about two to three pence (3–5¢) each.
The "card reader" was found to be an empty plastic box.
There are few times where 'Dowsing rod' is a step up. This may be one of those times.