The problem is that society as a whole hasn't really adjusted to having to explicitly make this decision with a user interface element. Previously the decision was made for you as a side effect of your mode of communication (phone calls to your best friend) or your location (a family gathering), etc. As Facebook et al. has become the de facto communication model for society, the default is to share everything with everyone, and no matter what your explicit setting some marketer has access to that information for the right price.