Actually, the Snowden files show that is happening for non-US Citizens/US-persons.
The NSA only has the legal obligation to obtain warrents for US Citizens not for anyone else. The NSA is unlikely to get involved in civil legal disputes but yes, it can go in and ask for Kafka's data from Google if he is living in, say, Germany.
Even for that there is a due process requirement, contained in E.O. 12333. Obviously the requirements are far lower but even there a random NSA analyst can't simply ask for the data, they'd have to get a supervisor within NSA to approve sending that request outside the agency.
But on the other hand I've not seen evidence that Google simply sells information on specific individuals or otherwise gives it away without that legal mandate.
Actually, I was referencing the AT&T "go ahead, it's AT&T's data and we can do whatever we want with it". That was so bad that Congress passed an ex post facto law relieving them of any criminal or civil wrongdoing.
The problem here is that Google's data on us belongs to Google. They can do anything they want to that data: take a crap on it, process it for better ad targeting, analyze social media trends and figure out who we associate with, and/or give it to people like the FBI/CIA/NSA.
Or, Google was hacked. That's also well within the realm of possibility as well. But I think governmental "persuasion techniques" like http://xkcd.com/538/ work much better.
Just look at the stories of Qwest former CEO. He said no.
is this really happening? can you give some evidence that google is willy nilly giving private data away like that?