Just because that's the interface doesn't mean, "Allowing the entire world access," is by design. I understand where you're coming from with the cultural angle in your other post. On the other hand, sometimes people leave things in the open with the idea, "what's the worst that can happen," or, "only authorized people will know about this, I don't need security." This doesn't signify an intention to let the world see, or a lack care about whether or not the world sees.