I worked in the cruise industry from 1984 to 1997. For some of this time, I was with one cruise line.
I learned that at this cruise line, accountants working on board ship would add to passenger bar bills charges for drinks that they had not consumed. They would be on the lookout for heavy drinkers, thinking that these people would lose track of their consumption and wouldn't question the number of drinks charged to their accounts. If passengers did challenge their bills, the extra charges would be removed and the "error" explained away as a mistake. If not ... they paid.
The accountants who took part in this scheme would later adjust the bills once again, this time to reflect the correct charges. This way, the bills would jibe with the actual bar accounts, and bar liquor inventories, and the cruise line would get their rightful due. The accountants would pocket the difference. And the passengers lost out.
In my experience, most of the onboard accountants were Filipino. The reaction of the cruise line, once it found out about this practice, was extreme: the same weekend it learned about this, it fired all of its onboard accountants Filipino or not. It made little effort to investigate as not to raise suspicion on the ships, or to find out who was guilty and who was not. It simply kicked out the accountants across the board.
Needless to say, the cruise line's outrage did not extend to reimbursing the cheated passengers. It said nothing to them, or about them, and it was understood that anyone who went public about this scam would be fired as well. When I worked in the cruise industry, management ruled by fear, and the people who wanted to keep their jobs knew to keep quiet ... or else. Nothing has changed.