These systems promise to technologically solve the human problem of undesirable material on the Net. This kind of claim seems to be based on the idea that ideas are things with a life of their own that can harm people's mental health in the same way that a biological virus could harm people's physical health. I'd take the biological analogy one step further. People raised in such environments fail to develop normal immune systems. Someone in quarantine like that often dies from an infection that a normal person would have resisted.
Children grow up eventually.
Much better to let them develop the critical thinking skills, the mental immune system, that can only derive from exposure to the complete range of human thought. For people who disagree with my view, it may seem attractive to buy a computer program that will relieve parents from the irksome necessity of paying attention to their children. I suppose people have a right to disagree with me, and parents even have a right to use this software. But I believe I have the natural right to look critically at any idea that comes my way. I have the right to take things apart and see how they work.