Question about Church?

I was talking to my friend today about his church and how the other week they watched a movie that gave reasons why the Harry Potter series is satanic and should not be read and how parents should not let their kids read any of these books. I was amazed. I had no idea this kind of thing goes on. That’s just like propaganda in my eyes… I just don’t understand. So, please I’d like someone to give me good reasons why this happens and I’d like to know if these kinds of practices are common in churches around the US. He also told me about the Church/Pastor slamming D&D, Trading Card Games, and more. Let me know or just give your opinion.