I disagree. You give a situation which is suggestive of the person learning they have cancer, and is a perfect example of how mass tracking can expose personal but information about our lives that we would rather keep private (particularly medical information, which I believe is the most vital kind of privacy threatened by these mass tracking schemes). But I wouldn't say that conclusion that you suggested is solid. It is equally plausible that the diagnostic center told the patient that results were negative, and the call to the mother was to reassure her and to the surgeon to cancel a preemptive appointment made by the doctor.

> The conclusions which can be drawn from that meta-data are far more solid than can be drawn from listening in to any or all of the phone calls.

This is just false. If you were a lawyer trying to draw a portrait of intentions with the metadata in court, obviously it would help your case if you could play the tapes and show what was said in each of the calls, so the other side can't propose equally valid situations like I did and create reasonable doubt.

I think we can be so fascinated by the power of having data, that much like the other powerful forensic tools used in the courtroom, we are eager to connect all the dots like we see TV shows like CSI doing. It can be difficult to remind people that more data (particularly meta-data and not content) produces more plausible hypotheses as often as it narrows them down.