Disgusted comments flooded the post which shows a man putting up his bare foot on the headrest of the seat in front of him.
People always say to put your best foot forward - but no passengers are happy to see your feet on board a long-haul flight.
Flying etiquette always stirs up a heated debate online and now a picture of a passenger putting up his feet on the headrest of the chair in front of him has gone viral.
Shared on Instagram under the account, 'passengershaming', the picture shows the passenger putting his bare feet on the side of the entertainment screen in front of him.
From the angle of the way he placed his feet, it appears that he was enjoying two seats to himself in the economy class of the plane.