I would suggest that the airlines subtly, but absolutely clearly make it clear to their customers that 1) Whilst onboard an aircraft, it's the captain and his/her crew that rules and you hafta do as they say 2) Failure to follow reasonable and sensible instructions from any member of crew is a criminal offence.
Basically educate people on the appliccable laws. When you board an aircraft, you're in a special situation, and you should better behave.
Could be printed on the safety cards, so everyone's read it after say 10 trips. Methinks problem today is that people think an aircraft is like any bar in Ibiza, and the crew are the bartenders.