I doubt it is, too. It's probably seeded - starting with one individual, they collect every call. Maybe for ever person they call, they collect every call that person makes. If they're really worried, they may go one layer further. It's a way of tracing networks.

So if one of those people calls you, your call record got collected. If you are one of those people, all of your call records got collected.

But hey, NSA, you want to pick me? Trace some of those spammers who keep calling my cell phone.