This article first appeared in The Windows Club.
“Besides the readable stuff, a boarding pass accommodates passengers’ last name and also the record key for the flight he or she is taking. Flier miles are also present on most of the reputed Airlines’ bar or QR code. Using this data on the website of the airline, people can get much more information such as details about flights booked for future, flier miles and other data that might identify a person.
With that information, anyone can change future flights’ seats, cancel the flights altogether and even reset the airline account so that the original passenger is no longer able to access his account right away.
. . .
There is a good amount of information on the boarding pass. But you need not panic if you can make sure that nobody else can get their hands on the pass slip with the barcode intact.”