200 years ago, William Godwin wrote an essay telling parents that they should not restrict which books their children can read. For example, they shouldn't ban their daughters from reading any novels.
Why did parents hate books? Because their kids might get ideas, or be influenced. Kids are gullible, you know? But far too stubborn and resistant to new ideas for parents to control or advise them.
Now that there is an even larger threat than books (TV), parents have given up on keeping kids away from books, and actually encourage it so as to distract them from the TV. Television is a medium capable of expressing text just like a book, but also capable of conveying pictures and sounds, so it's quite a bit more powerful than books. And people like TV better, and want to spend a lot of time using it. When people really like something, that's called addiction, and it must be stopped.
I'm not joking. There's even "email addiction", and it's just like cocaine.
Here's Godwin's book, which is out of copyright and free.