I brought up my kids using the computer. Since age 5. I always had them playing educational games but as they got older they found the internet and video games. I don't monitor them and allow them freedom to do what they want on their computers. So far they have all turned out fine. They are in University or College and all of them have jobs. No psychotic events from my kids.
You are very fortunate that the children did not find anything wrong with the Internet and developed normally. But for safety, you need to control children.
Do you understand that children not only have access to the Internet and other dangerous things at home? How can they be protected from the fact that it can greatly harm their psyche and the perception of the world?