theres 2 hairs to split, the collection of metadata on millions of Americans not even suspected of commiting a crime, and the actual recording of phone calls.
The meta data part I think isn't really debatable and just by itself is enough to call the program a gross violation of the 4th amendment, none of these people who are having their information compiled where ever accused of a crime.
I think we both realize that the internet is too new for as many protection laws to be written for it, so any digital information (including internet phone calls, all contents of emails, text messaging, anything you backup to the cloud ect ect ) are gone through.
You might have a point that they don't currently record every single phone call(which we will find out more about in the future), but if that is your red line man are they doing everything in their power to grab every bit of data even remotely related to an individual.
even without the recording of everyone's phone calls just the act of compiling metadata on every american kind of violates the "innocent until proven guilty" angle.