"If they were servicing extremely-broad FISAs like Verizon's "send us all your phone metadata" then the distinction would be academic, but both Google and the NYT seem clear that Google hasn't accepted anything on close to that scale."
Maybe I read it wrong but Verizon was ordered by the court to do just that and to shut up about it. I doubt they were asked to accept, just the court ordered it and it is so because it became a 'legal request.' I have to wonder what Google, Microsoft and Facebook were asked to provide to NSA in large scale. If they can have all calls to see if anyone calls certain "terrorists," why not get a log of all Skype calls, FB likes, messages, Google searches etc to see if anyone is linked to "terrorists" or searching for related materials?