I suspect you use the knife example as an analogy. My daughter has a hatchet. It scares the heck out of me. I don't let her use it when I am not around or children other than our own are with her. But she loves it, and I have attempted to teach her correct and safe usage.
Technology can be as dangerous as a "sharp knife." Being given safe and monitored access to it and becoming familiar and comfortable with it will likely result in a more positive and healthy experience with it when unfettered access is suddenly thrust upon them.