An RFID transponder having an adjustable response field strength including a determination circuit formed to determine a quantity which is derivable from a field strength of an electromagnetic field prevailing at the location of the RFID transponder, a comparator formed to compare the determined quantity derived from the field strength with a threshold value, wherein the threshold value is based on the adjustable response field strength, which is higher than the minimum field strength required for the operation of the RFID transponder, and a deactivator formed to deactivate a functionality of the RFID transponder if the derived quantity falls below the threshold value.