I respectfully disagree. My mother let me read pretty much anything I wanted all my life, and at around 12 I started reading books like 'A child called it' and other similar books. I really didn't have the maturity to stop reading them, I got a weirdly morbid facination with them for a few weeks

Needless to say they messed me up, especially the ones with certain abuses, leading me to having issues with my partner now because it set a hatred for all of that sort of thing in me from an early age. I don't think all books should be banned, and I think that the ones she was reading weren't that bad really. But monitoring what your younger kid reads is not the worst thing to do. I wish my mum had paid a little more attention to what I was reading

Again, just my opinion and my own experience, its not the same for everyone