They are told straight out not to read or watch or listen to anything that has mystical, magical or supernatural themes.
When I was "in" that meant, I didn't let my children read Harry Potter, Lord of the Rings or even Snow White. Funny, I let them watch Wizard of Oz, Cinderella or Beauty and the Beast - but not without some hesitation. I knew many who disagreed with my husband and I loving Star Trek - they disagreed with the idea that God could have created life on other planets.
P.S. We now own them all !