Reply #13: First of all, they are not only mining numbers...

[Karmakaze]

They do of course know who those numbers belong to - a reverse directory lookup will give that to them.

But what they are really mining is who you call, and who they call, and who they call. Say for example that you ring me. Now they know you and I have a relationship of some kind. If you ring me more than once, they know it is not a passing relationship. If you ring me frequently or in some kind of pattern, say every Tuesday, they can surmise that there is more than just a casual relationship, and if it is very regular (as in same time each week) then they can guess there is some kind of organisation to our relationship, rather than just say friendship.

Now they do the same to me and see who I ring. Now imagine I ring a number, the same number, minutes after you rang me. Now there is a chain forming. By studying such chains and comparing them with known targets, they can discern patterns of behaviour.

You have heard them talk about how they detect a threat by the "chatter" well this is it. It's called signals intelligence. You can tell a whole lot about what is going on by simply finding out who calls who, when. You don't even have to know what was actually said, yet from the patterns you can detect things you wouldn't think possible without actually knowing what was said.

For example you and I have a regular call. Once a week for months. Suddenly there are a flurry of calls in one week then silence. You could surmise from this that something was being planned. When the flurry occurs the final preperations are underway, and when the calls stop the plan is being put into action. Now if it was a woman calling her parents this could mean a marriage. But if it was apparent strangers, who have no other common feature, then perhaps it is a terrorist plot.

Now imagine someone I called, called someone who was a known terrorist. Now you have a whole network of people identified as being in regular contact with a terrorist because they were in contact with me. That would include YOU, and you have now just joined the ranks of terrorist suspects. Now everyone who has called YOU regularly is ALSO a terrorist suspect, and so on.

All that from just a number.