"Essentially, every long and short distance phone company works for the Federal Government.."
"Tell me how it works."
"We have lines installed from the 114 Signal Transfer Points in every phone district to a pair of Cray-YMP's at the Fort. Every single AT&T long distance phone call goes through these switches and is labeled by an IAM with where the call came from and where it's going. What we're looking for is the high usage digital lines. Including fax lines. So the phone company is kind enough to send us a list of every call. We get about seven million an hour."
"We can handle that?"
"We have enough to handle ten times that."
"I forget about the international monitors. That's millions more calls a day we listen to."
"Yessir. The computers go through every call and make a list of digital calls. Then we get a list of all billing records and start crunching. We compare the high usage digital lines with the phone numbers from the bills and look for patterns. We look to see if it's a private or business line, part of a private PBX, hours and days of usage, then who owns the line. Obviously we eliminate a great many from legitimate businesses. After inten- sive analysis and profile comparison, we got a a few thousand candidates. What we decided to look for was two things.
"First, we listen to the lines to make sure it's a computer. If it is, we get a look at the transmissions. If they are encrypt- ed, they get a red flag and onto the Hit List."
"The President bought this?"
"We told him we'd only need the records for a short time, and then we would dispose of them. He agreed."