This is a fantastic article by John Foreman about the implications of Disney's magic bands - self-tracking as a utility - which moves beyond Disney to take a quick look at what happens when you invert our hyper-tracked digital space and interpret it in daily reality. It's not pretty.
Sometimes someone goes out and does all the research and writes up all the words you felt you needed to write. This is one of those articles. Please read ALL the words, right down to the end. It is important that we make these 'opt out' decisions in an informed state about what we are all giving up pretty readily.