Not necessarily; it may have been a very important source that has dried up or has been superseded by alternatives. The phone program was launched prior to the

Not necessarily; it may have been a very important source that has dried up or has been superseded by alternatives. The phone program was launched prior to the iPhone and Facebook (even though we only found out about it after both). It may well have been very important up to at least 2012 (6 years into Facebook, 3 into the iPhone/ android boom) when we learned about the program and the NSA defended it. Since the revelation seven years ago, it could well be that targets of the NSA are no longer using communication channels where phone metadata is useful.