When personal data is easily swapped and shared on the network, a couple of keystrokes gets you, say, a United reservation, frequent-flier number included, plus the kind of rental car you like and your hotel reservation--even listings of the movies or restaurants that have opened since your last visit.
Evidently Delta is not worried about it because not only is the number printed but also the record locator number for the reservation and of course the name of the passenger.
Conscious efforts are made in and around the town to ensure that visitors explore such attractions without spoiling them, so it is forbidden to set foot on any trail or enter any river without making a reservation and each attraction limits the number of tourists that can visit at any time.
This suggests that, while OpenTable is already the single largest provider of online restaurant reservation services, it is also witnessing almost 40% annual growth in the number of diners it seats.