Before I started my current job, I worked for Go at STN, dealing mainly with large groups. We used to have a particular problem with groups of teenagers who would be rude to the CC, steal seat belts and life vests and generally cause mayhem. Following an adverse report from the crew on the first sector, I used to have great pleasure in meeting them at the gate for the return sector, taking their passports from them, and telling them that they would be given to the aircraft captain. If they behaved nicely they get them back, any bad behaviour and they could get them from the police on arrival. Strangely enough, they were always well behaved after that!