A card reader module (10) is described. The module (10) includes a trap mechanism (20) operable to trap a card (60) within the module (10) in response to the module (10) detecting a card (60) therein that cannot be transported. The trap mechanism (20) may be implemented by a width switch (22) and associated interlock (24), where the width switch (22) is located within a throat portion (14) of the card reader module (10). On detecting a jammed card, the width switch (22) is locked to prevent removal of the card. The module (10) may also include a magnetic head (28) operable to erase data stored on a magnetic stripe (62) on a card (60) if the trap mechanism (20) is not able to prevent removal of the card (60). A self-service terminal (70) for preventing fraud and a method of preventing fraud using the module (10) are also described.
