From classics like A Wrinkle in Time and Catcher in the Rye, to modern day works like Harry Potter and Twilight, there have been attempts to remove books that are considered inappropriate by some people. People who have decided the "not right for me" should really mean "not right for everyone."
I fully support someone's right to buy or not buy a certain book based on their preferences, but when people push their values onto others by saying certain books shouldn't be allowed on the shelves at all, it usually speaks to fear, ignorance, or a combination of the two. Just look at how many books with LGBT themes or characters end up on challenged/banned lists. I've heard statements like, "Well, it could lead young people to believe that [being gay] is an acceptable lifestyle." Seriously? All that demonstrates is a complete lack of understanding of human sexuality.
As a parent, do I have the right to temporarily "ban" a certain book for my 7-yo if I feel he's not old enough for it yet? Absolutely. I'm his mom. I also "ban" him from R and most PG-13 movies, despite the fact that most of his friends are allowed to see them (I tell him they'd be called PG-7 movies if they were meant for his age). But I allow him as much freedom as possible to choose his own books, because at some point, he'll be able to read whatever he wants. My job will be to keep the communication lines open when he has questions, and I realize that at some point his questions will involve deeper issues than how a fake tail was attached to a dolphin.
But all kids are different. What's right for my kid might be wrong for someone else's, and vice versa. Trying to control what all kids read based on my personal perspective would be extremely ego-centric on my part. Unfortunately, there are a lot of ego-centric folks out there, who cloak their book banning attempts under the guise of "trying to protect our children." I'd rather empower my children and give them all the knowledge they need to make their own informed decisions.
It's interesting that most of the books that have had the biggest impact me, books that made me think about them long after I read them, have been on these sort of lists at one time or another. Why is it that books that make you question things--or heaven forbid, make you think--are the dangerous ones?
What about you? What is your favorite banned/challenged book of all-time? Mine is probably a tie between The Giver, and Go Ask Alice (which I read at a very young age BTW, and it had a tremendous positive influence on me. It was part of what motivated me to become a psychologist.)