Sounds like one of those situations where you're damned if you do and damned if you don't. Even the most eloquent bitchslap directed at such users, even if you disguise it as user education, can still cause strife. :/
Most of my military experience followed this maxim. For example: You witness your squadmates doing something against the rules. Do you do the Official thing and report that to your unit commander, as you required to by guidelines and the definition of "good soldier"? Because if you do, now your entire squad will ostracize you, make your life complete shit, and possibly leave you to die on the battlefield. If you don't, you had better hope they don't get caught, because if it comes out that you knew about it and didn't say anything, now you are in just as much trouble.
Most of my military experience followed this maxim. For example: You witness your squadmates doing something against the rules. Do you do the Official thing and report that to your unit commander, as you required to by guidelines and the definition of "good soldier"? Because if you do, now your entire squad will ostracize you, make your life complete shit, and possibly leave you to die on the battlefield. If you don't, you had better hope they don't get caught, because if it comes out that you knew about it and didn't say anything, now you are in just as much trouble.
This happened literally every day.