We've long had a problem with RPG books being banned in prisons. I even worked on this back in my early days with CAR-PGa, 20–25 years ago.
A few days ago, The Marshall Project put out a database of works banned in state prisons for each state that keeps a list. Unfortunately, I know from experience that frequently these decisions are made on an individual prison level rather than being recorded on a statewide list somewhere, and many states don't actually keep centralized lists of what they ban at all. Still, they got more than 50,000 titles from across half the states.
The lead image for the database page includes the AD&D 2nd edition supplement Anauroch. Have fun hunting for more RPG examples!
—M. Alan Thomas II