Like?
oh, I don't know, maybe staying in power? appeasing lobbyists? keeping people stupid enough to not question things that the government does? or maybe getting people to think that they are inherently benevolent and would never do anything with their power that would be morally questionable?
and if you think that they wouldn't do any or all of the above just to stay up there in Washington and/or keep hold of any power they can grasp, I feel sorry for you.
If they have all this data on you, you better hope you never do something the government doesn't like. This is a lot more serious than many of you seem to believe, if they can pick out the people who are likely to oppose the government, or something they are doing, they can keep a close watch on them and monitor their actions. It's not just about terrorists, as they would lead you to believe, it's about keeping control over the population.