On 2006-05-15, retired Admiral Bobby Ray Inman, former director of the NSA, claimed that he thought that the USA Today story revealing that the NSA may have a database of the phone calls made by “tens of millions of Americans” was greatly exaggerated because the NSA didn't have the resources to store that much data. This is entirely untrue. This capability was a fantasy in 1981 when Admiral Inman left the NSA, but today, it is whithin the average American's budget.

If the NSA wanted to store the last 100 phone calls made by 50 million Americans, here is a liberal estimate of what that would require.

• Each individual domestic telephone number could be stored as a 30-bit number¹
• For each of those 50 million phone numbers, you would want to attach a list of 100 called numbers, with dates and durations of calls. A phone number is 30 bits, the date could be stored as a 40-bit number². The duration of the call could be stored as a 19-bit number³. So each call record would add 89 bits. Adding 100 of these records would add 8900 bits to the record. So an individual's call record would take 8930 bits; roughly 1 kilobyte of data.
• So the total amount of space necessary would be about 52 Gigabytes.

baber.com sells a 60 gigabyte hard drive for $189.

This is my crummy, quick estimate, the very smart people at the NSA have surely thought of much more sophisticated storage methods. Also, they don't have to store all of these records to accomplish all kinds of creepy traffic analysis. The point is that saying the NSA doesn't have the capacity to do this is a red herring.