I know one story from TOS, where an anonymous passenger had reported the cockpit crew for drinking while they were flying OSL-TOS. They were arrested in the terminal and brought to the local police station with no explanation.
It turned out that one of the stewardesses had brought some cans of mineral water to the cockpit crew that looked very similar to the Mack Beer cans.
This is probably not the same story, but it certainly shows how touchy this issue is.
Nick.