REALITY TV contestants are used to revealing personal information to a national audience, but a blink-and-you'll-miss-it moment on last night's episode of MasterChef could have taken that a bit too far.
Sunday's episode of the hit series opened with contestants Tamara and Sarah arriving at Melbourne Airport ahead of their flight to Tokyo in Qantas Business Class as part as their reward for taking out last week's Team Challenge.
The excitable pair headed to the Qantas desk to check in to their flight, and then the camera flashed to a close-up of one of their boarding passes - proof of their glorious ticket to Tokyo for MasterChef's Japan Week.
As Instagram users know, no trip really starts until you flash your boarding pass in an obligatory photo or video at the airport.
But eagle-eyed MasterChef viewer Steve Hui, the chief executive of rewards points management site iflyflat.com.au, said this was an example of what not to do, because there was a lot of critical personal information identity thieves could very easily get from a seemingly innocent boarding pass.
And it's not always your name that will expose you - the best information could actually be gleaned from the barcode.
"(Boarding passes) can reveal your full name and frequent flyer membership numbers, which others can then use to hack into your frequent flyer membership, or at the very least, be a nuisance which results in your account being locked due to too many incorrect password attempts," Mr Hui told news.com.au.
"The barcode can reveal further information, such as passport numbers, full name [and] passenger name record (PNR) which can access flight booking details and ticket number."
Mr Hui warned the information could be used to access airline systems to find out further information on individual passengers or even cancel the flight.
"Some people cover up their name and PNR, but don't cover up the barcode. Barcodes can be read by barcode readers."
Mr Hui, who is known as "the points whisperer", also said Qantas and Virgin Australia were rolling out two-factor authentication to protect their frequent flyer members.
Still, he said sharing images of your boarding pass in public was never a good idea.
"The key message to share, is that you think you are sharing very little, but in fact you are sharing a lot more than you want to," he said.
"Don't share or leave your boarding pass in public, it is very private."
News.com.au has approached Channel Ten for comment.