Banned books

We have been talking alot about banning books and what books should and shouldn't be banned. I don't believe that books should be banned from libraries. I believe that any person who wants to extend their knowledge by reading a book should be able to choose any book they want to read. Weather it has harsh language, sexual content, or violence, the person reading the book is reading it to gain knowledge of whatever the book is about. There are so many good books that portray at least one of them three "bad" qualities that really are meaningfull books to read.
On the other hand, I think that if a teacher assigns a book to the class and a childs parent doesn't want them reading that book for a certain reason, the teacher should allow that student to read a different book instead. You cant blame parents for wanting to protect their childs innocents. I understand that kids are going to see, hear, and talk about things that no parent wants their child to see, hear, or talk about, but I believe that they do have the right to take a stand and decide whats write for their child.