I'm sorry, I still can't get my knickers in a twist about this. If someone is focused on one particular person to the point that they drill down to the level that they graph the frequency and timing of telephone calls, odds are they're a "person of interest" for some important reason (I don't think budgets or time constrictions allow tracking everyone to that level.) And if you're of that much interest, odds are also that the same (or very similar) information could be found out by old-fashion detective work (sifting through your trash, tailing you, etc.)
But even if we just focus on the supposed wealth of information from metadata, isn't that compromised by the fact that many people have/use more than one phone (home landline, personal cell, work cell, work landline, a coworker's landline, prepaid burner phone, friend's house phone, friend's cell, random "can I use your phone for a second" to a stranger?"
Anyone who is doing anything covert (even something as non-national-security-threatening but simply disgusting and sleazy like having an affair) who is stupid enough to use one phone is probably too stupid to look before they cross the street. Pure Darwin Award material.
And if some government bureau is throwing out some sort of dragnet to find groups of people who act in a way they don't like, they'd find much more usable info reading all of our posts on places like BoingBoing. (Because if you think your user IDs are not trackable, you're dreaming.)