Karn's note...

[Peter Wayner]

I believe the novel implied that the magic box didn't do voice
recognition in the sense of identifying the words being spoken.
It just said, "Hey, that sounds like Bob Smith on line 42." The
point was that these guys were jumping around from phone to
phone. 

But, I agree with you that traffic analysis should be much easier
now with all of the ID tags. I think the Clancy box would be
too much overkill because people really don't use that many 
telephones during the day. Especially now that they call carry
pocket cellular phones. 

-Peter