A friend of mine, who is a TAP F/O, told me the following episode which he experienced himself.
Some years ago a large Danish group - a couple off school classes - were in Portugal traveling on TAP. On the way out they played havoc on the plane and created the outmost discomfort to other passengers. The cabin looked like a disaster after deboarding in Lisbon.
On the way back home some days later it was another crew, but they had been told about their behaviour.
At the gate the leaders of the group were called. They were taken to a separate room.
There the captain told them that if the slightest episode happened on their way to Copenhagen, then he would turn around and land in Lisbon, they would deboard, be taken care of by police, TAP would never see them again, and there would of course be no refund.
There were some noisy arguments to which the captain said: "I have four stripes, it means two things, I give orders, and I don't listen". And then he left the room, leaving it to some flight attendants to show them the way to the gate again.
The flight to CPH was as silent as on a cargo plane, and the cabin hardly needed cleaning at CPH.
Regards, Preben Norholm
Always keep your number of landings equal to your number of take-offs