If you look on any friend's timeline on Instagram or Facebook during their great vacation, you may see them posting images of their boarding passes. After reading this, you may want to discourage them and suggest to take them down.
A report by Krebs on Security has cited the security risk for posting images of your boarding passes or even throwing them in the trash. It cited that the barcode and airline information such as your frequent flier number could jeopardize your next trip. Simply, the boarding pass codes may contain more data than your expected boarding gate and time information.
In a recent cyber-security conference in Berlin last year, security experts Karsten Nohl and Nemanja Nikodijevic said that airlines essentially treat the six-digit booking code known as a PNR as a temporary password while people travel, attaching it to everything from boarding passes to luggage, along with the passenger’s name. “You would imagine that if they treat it as a password equivalent then they would keep it secret like a password,” Nohl said. “Only, they don’t, but rather print it on everything you get from the airline.”
Some of the information included on your passenger record could include your passport number, expiration date, and even passenger preferences you make on airline websites.
For most airline booking sites, all it takes to access your travel information is the booking code and your last name to access the your travel information. With that, anyone could change or cancel your reservation.
The take-away: never post your boarding pass online and destroy it after your trip. You may also want to store it in a safe place in the event the airline doesn't record your frequent flier miles for your trip or something happens during or after your flight.