In order for someone (the NSA?) to track a phone and do whatever they need to do, they need to have a warrant and what-not.
That's like deliberately sending all your living-room conversations (yours and your family's) online for analysis for God-knows-what purpose.
You trust Amazon that's good for you then. I don't trust anybody with admittedly uncontrolled access to all table conversations my family will have in the future.