Unfortunately the browser isn't the only place to access user-generated content. Take for example a Twitter client, just by nature of being a Twitter client and

Unfortunately the browser isn't the only place to access user-generated content. Take for example a Twitter client, just by nature of being a Twitter client and theoretically having access to the public timeline with mature content is enough to get a 17+ rating. Or...name any app that would need a browser built-in, presumably because the user would come across many links while using the app (and of course the dev wants to provide a better user experience via not having to quit the application)...where would the links come from? It wouldn't be just the browser that needs restricted.