I do not believe that Google is voluntarily handing over any sensitive customer data to the NSA without legal compulsion. I would not be surprised if intelligence agencies around the world including US based ones target Google's communications (probably in full accordance to each agency's authorization) but that would not be with Google's cooperation.
I believe that Google is taking steps to protect customer data from all bad actors, including Government agencies. One initiative that was underway around the time I worked at Google was to encrypt all the data-center to data-center traffic at Google in an attempt to frustrate anyone who was tapping Google's backbone links.