Originally Posted by
docbert
This potentially depends on the exact system in use...
Yes, of course.
Originally Posted by
docbert
Generally the keys do have information about the room number, check-out date, and some additional information that the lock can use to lock-out other keys. The locks themselves are generally NOT linked to a central system, so have no way of validating information, or of receiving any information about which keys are in use.
Are you sure about that? If the card contains the room number and checkout date, what's to prevent someone who finds a dropped keycard from just reading it and accessing the room, or changing the checkout date on the card? Or even making a bunch of cards for different rooms and using them during the day when most hotel guests are out of their rooms, particularly in properties/locations with a large percentage of business guests?