There is information out there about fraud and theft in relation to the dining cars on Amtrak, like this -- a bit old now but interesting:
"Fraud, Waste, and Abuse Are Long-standing Problems
"Between March 2003 and January 2010, we identified 903 theft, dishonesty, and policy/procedure violations by 306 LSAs, and issued 447 administrative referrals to Amtrak managers.
"The recurring schemes described in this report involve the falsification of documents to conceal missing food and beverage revenues and inventories. Specifically:
"Inflating first-class meal checks. This scheme involves adding items to first-class passengers meal checksmeals are provided free to first-class passengersand selling these items to other passengers for cash.
"Selling non-Amtrak items. This scheme involves smuggling non-Amtrak items on board a train and selling them to passengers.
"Shorting cash register sales. This scheme involves selling items for their retail value and ringing up smaller amounts, with LSAs pocketing the difference.
"Stealing inventory. This scheme involves directly taking dining car food (rice, oil, eggs, and potatoes) and other itemscomplimentary beverages, paper products, and open wine bottles.
"Providing items at no cost. This scheme involves providing customers with complimentary items and providing free drink refills without authorization."
There are recommendations in the report to reduce the abuses; whether or not implemented I don't know.
https://www.amtrakoig.gov/sites/default/files/reports/on-board_food_and_beverage_6_23_11.pdf