Lord of the Flies is known as being one of the most controversial children's books ever written, telling the story of a group of school children who become stranded on an island and quickly descend into disturbing levels of chaos and violence.
One of the reasons this book is controversial is due to the intense violence of certain scenes, which might upset children. For example, Piggy is intentionally killed with a rock, which is described in the following passage:
Piggy fell 40 feet and landed on his back across the square red rock in the sea. His head opened and stuff came out and turned red. Piggy's arms and legs twitched a bit, like a pig after it has been killed.
With passages like this, some parents are unsurprisingly uncomfortable with their children reading this book. Another act of violence in Lord of the Flies is when the boys cruelly kill a pig, which is squealing in pain. This is described using grotesque imagery by Golding, with passages that would make adult readers wince.
Unlike other children's books, The Lord of the Flies shows the darkest aspects of human nature, presenting children as being capable of sadistic acts of violence and brutality. While Golding is suggesting that humans are violent by nature, this nuanced message might not be understood by young readers. As such, there are concerns that children might get the wrong message from this kind of book.
Another key issue parents and educators have is the representation of bullying. We see bullying throughout the book, directed particularly towards Piggy, who struggles with asthma and poor eyesight. Piggy is called cruel names such as "fatty" and is physically attacked on a number of occasions. This kind of relentless bullying is perhaps not the best thing for young audiences to be reading, not only because it might upset them, but also because it might encourage bullying.
Considering this, it is perhaps understandable why parents, schools, and libraries banned children from reading this book. Young people are arguably not the best audience for this kind of information, as they might not be able to fully grasp the message Golding is trying to convey.