The problem is, in 99 out of 100 cases, alcohol. Some people just can't handle it and, I'm sorry to say, but the LCC world of today has brought some less desirables into the cabin, who wouldn't have had the opportunity before. It is, as good as always, males in the age 18-50, who've had a drink or two before leaving home, then a couple more in the bar and a swig off the something in the plastic bag on the way out to the gate.
This is where my staff meet them, and they've got a very, very difficult job on their hands. We hire and train them for their friendly and serviceminded personality, whilst trying to dress them up for the odd idiot passing their way. But it's service and friendly we're mostly looking for, the exact same thing psychopaths are looking for in a victim. And, yes, we do have to serve psychopaths; no booking machine are yet to ask 'are you a complete moron or suffering from any disturbing psychological trauma?'
We do our best to keep them off the aircraft, sometime to the physical or verbal detriment of our staff. It is, you understand, entirely their fault the aircraft left on-time and you didn't make it, because there were Jägerbombs on sale in the bar. We see the worst kind of verbal abuse, and on very rare occasions also violence. It must be a big man indeed, punching a 60kg, 160cm, girl out because she was doing her job.
We've also had our female staff stalked, including one particularly nasty person sneaking up on her back as she was walking down the pier, promising to do the nastiest of things to her, attempting to grab and chasing her into a toilet where he stood outside and basically promised to rape and kill her. That girl, by the way, is still receiving psychological help and is unlikely to return to work. Because a drunken passenger couldn't behave himself and threatened other passengers in the departure lounge, upon which he was denied boarding.
How to stop it? Only by making the rest of us 'suffer' for the actions of a, relative, few: By banning the sale and consumption of alcohol in airports and onboard commercial aircraft. It was possible with smoking, surely it's possible with alcohol as well.
As for duty-free booze: Can only be bought on arrival and never brought onboard an aircraft as carry-on.