What are SW's experiences with banned/forbidden books?

I ask this because I just remembered an incident in 6th grade involving The Girl who Played with Fire. I had brought in in to read for this mandatory reading hour and the teacher called me outside and took it from me for being "inappropriate for her classroom." I told my parents about it later and they got the principal involved, which ended in my favor, but I'm still so confused about that teacher's mentality. Who gives a damn?