What does the NSA need call data for?

Report: NSA Has Call Data On Millions
Man, that was close. They almost got away with it, but thanks to CBS another government conspiracy has been brought to light. What in the heck would the NSA need our phone call records for anyway? Sounds like they're up to no good. Their capabilities to protect us should be more than adequate with that mind reader thingy they use to keep tabs on the bad guys. And of course it only works on the bad guys. They need to just stick with that alien technology they got from Area 51 and leave our phone records alone.

Next thing you know, they'll be wire tapping cell phone conversations... as soon as they figure out which wire to tap into.

I'm drowning in sarcasm.