#WritersCoffeeClub June 1 - Are there ethical principles fiction must adhere to? What are they?

No. There may be some, or many, to which it *should* adhere, but that's not the same question.

It reminds me of people saying "You can't do that!" to people who patently are doing that. The word you're looking for is "shouldn't" or "mustn't".

("You can't alter history! Not one line!" -- The First Doctor)