The teenager is seen to argue with the ScotRail conductor and refuses to leave the train, but clearly didn’t count on the burly traveller taking matters into his own hands.

The ‘big man’, presumably displeased at the delay to the service, gets up and grabs the youth by his collar before frogmarching him off the train.

The carriage erupts into applause as the vigilante returns to his seat, with one passenger shouting: “Cheers, big man.”

The video was uploaded to Youtube and has been viewed almost 200,000 times in the past three days.

Whose side are you on? Join the conversation on our Facebook page…

Though the ‘big man’ did what most of us must have fantasised about at some point during a commute, a ScotRail spokesman said: “While we welcome the public’s support of our zero-tolerance stance on anti-social behaviour, our staff are trained in conflict management and we do not expect members of the public to take matters into their own hands.”

He added: “We are investigating the incident, which appears to show a person travelling without a valid ticket, refusing to pay for the journey, and swearing at a staff member in full view of customers.”