But then you need to add each new contact to a group that rings. I use an app that blocks anybody not in my contact list. That's the single feature I use for th

But then you need to add each new contact to a group that rings. I use an app that blocks anybody not in my contact list. That's the single feature I use for that app. They probably mine all of my all history. Why can't this feature be a simple checkbox in the phone or contacts app?