You can't child-proof the world. And even if you could, it would be a bad idea. It's foolish to think that you can keep adolescents away from everything that is indecent. If kids want to find pictures of naked people or real live naked people, then somehow they will. Children are small human beings.
Human beings are the cleverest critters in all creation.
If they want something bad enough, they will find it. If we're doing our jobs as parents and teachers, our children are better equipped than we are. We're supposed to pass all the good ideas and skills we know down to them. They, in turn, are supposed to have new ideas to add to the heritage and pass them down to their children and so on and so on. And that means that on the whole they will beat us in a battle of wits.