Experts warn about danger of posting photos of your boarding pass online as the document can be used by a hacker, Evening Standard reported.

The six-digit codes printed on both boarding passes and luggage tickets (PNR) can be used by hackers to retrieve personal data, the newspaper writes quoting Israel-based security researcher Noam Rotem.

PNR contains information about the flight, and hackers can steal your flights and frequent flier miles or change your seats.