You know the witness for T-Mobile, Raymond MacDonald? I worked with him for Law Enforcement Relations projects. We worked with the DEA, the NYPD, FBI, etc. to streamline the process of responding to subpoenas for information. I left there two years ago for my home in central KY.
We had a myriad of data sources from which to pull all sorts of data. We were required by law to save it for at least 7 years. Though the data was frighteningly detailed, voice call content was not part of it.
Now, in the last two years things may have changed, so my information becomes antiquated with every passing year.
Surely you are aware that Eschelon has recorded every voice or data call made since it was cereated many decades ago?