This reflects one of my concerns, that the government can get access to individuals' information through a third party without those individuals having any legal means to contest the government on the matter. The Kansas AG who is constantly trying to figure out new ways to try to intimidate women who have would get abortions comes to mind.

But with your background, I am curious as to your take on the effectiveness of this effort. I would imagine that they would have to have some nugget of information with which to filter through the billions of calls. If so, why go through so many other peoples' data, too? How does this give them information that they wouldn't just get from monitoring all connections to a particular individual? If they don't have a particular individual or group they're targeting, then how can they tell the difference between a house church, my sister-in-law and her friends, and a terror cell? Seems like they could be more interested in other data that has nothing to do with terrorism.

Just getting raw CDR (call detail records) from the switches would be a huge boon in any country. Most people call very few people frequently, perhaps 5x more on a regular basis and the rest randomly. You wouldn't have to know that A has a pre-paid cell phone and a landline, you would just see calls at the right time in this nexus and assert that A has two phones. Good enough.

Sorry not to have gotten back to this sooner, but I couldn't get to the site last night or earlier today.

The phone companies may "own" the data about my call traffic, but that is inherently connected to me by dint of my phone number. Reverse directories are freely available on the internet, at least for landlines.

The news story I read about this yesterday said that they were looking for the data so that they could go back in time after someone had acted and look up who he had been calling, as if the issue was to be able to look up historical information. That may be a reporter misunderstanding the program, since your description sounds more like a predictive model.

Part of my concern is the propensity for government to misuse data. What do they do once they have identified a "terror cell"? Do they then send in SWAT commandos with poor trigger discipline because "we can't take the chance of waiting"? Do they monitor them with warrantless wiretaps and searches? Do they actually follow the law and get a rubber-stamp warrant from the FISA court? If it turns out that they are not a terror cell, and the group they are monitoring hasn't been shot, do they keep all the information they've gathered or is it disposed of? I don't trust people who have no shame committing a felony by firing someone for their political beliefs not to abuse any information they collect.

I specified house church in my earlier question for a reason, because they are a cell structure and tend to have tighter social bonds than traditional American churches. I would think a group like that would have communication patterns that would be harder to distinguish from other types of cells. Likewise for my sister-in-law and her friends, who have the ability to spread information amongst themselves that would boggle a mass-media mogul's mind. I would've expected that terrorists would be working in 5-6 person cells and not be in frequent contact outside of those cells, so I just have a hard time figuring out how they would look unique as far as traffic statistics go.

What use is knowing that person A has a landline and a pre-paid phone unless they are connecting those phones to a specific, no-longer-anonymous person? That is where I have a hard time seeing how this program standing on its own would be useful to find terrorists.

The difference to me with the hardware chain is that I have a choice of giving them personally identifiable information when I make a purchase. I have the option to obtain the steel pipe by paying in cash if I don't want them to have information about my habits. If I choose to use a credit card that can be tied to me then I have made that choice based on convenience and I have less room to complain about it. I don't have that option with a phone company, so I think the privacy safeguards should be higher.

I think what is sticking for me is that, if this information needs other information to be useful, what is the 'need' for the massive collection of citizens' data? If the phone data leads to other useful information, let's hear that. It doesn't make this any less of a concern to me, but at least it would show that they have a clue. I doubt that there is any way they can defend the program. To say that it is effective magnifies the violation of privacy; to say that it is harmless begs the question of why they would do it in the first place.

I see your point about house church vs. terror cell, but I would think, though, that a construction crew or any number of companies organized to do site work and utilizing a supervisor would have similar leader-centric call patterns. After reading Linked by Barabasi I wonder if social networks tend to have more of those nodes/leaders than you might expect instead of the peer-to-peer distribution. If you have any pointers to public white papers on this topic I would be interested to hear them (I had of course assumed that you didn't have any clearance-level information on this before I asked you about it).

I appreciate your educated comments on the topic, but I am afraid they haven't done much to comfort me that these guys aren't just using any excuse to invade their own citizens' privacy.