Anything adult in nature would live on playboy.red. Who would enforce it. Ultimately, the government. Congress would set up definitions of adult content and penalties for those who don't abide. How it protects children.
All users have to do is set up a filter in their browsers for the .red domain.
Libraries, schools and parents have an easy, simple mechanism to protect children. How it protects free speech. This plan doesn't stop people from saying or showing anything they want. They just have to label it as adult content by placing it on a page with the .red domain name. If you feel as strongly about creating a Red Zone as I do, please write to your elected representatives.