I made a similar estimate (based on the premise of crude voice recognition of calls, not storage) in Feb 2006. http://ivymike.blogspot.com/2006/02/could-nsa-wi

I made a similar estimate (based on the premise of crude voice recognition of calls, not storage) in Feb 2006. http://ivymike.blogspot.com/2006/02/could-nsa-wiretap-everybody.html http://ivymike.blogspot.com/2006/02/could-nsa-wiretap-everyb... I used a different methodology to come up with call volume; I looked at the Inter- and IntraLATA numbers (in 2004, which was the lastest available when I did this analysis.) My number was 700 billion minutes per year. This new estimate is around 1100 billion minutes per year, which seems very plausible to me.