"rudy (r.) rawlins" says:

...

Normally, one can only determine the endpoints of a conversation. With clipper, however, one can deduce a lot more, since when people move around, go to hotels, phone booths, etc, you can still track their clipper serial numbers.

Perry

Maybe we are missing something here, when people move around if they simply use their hotels phones, phone booths, et al, how can one track their clipper serial number? Unless there is a personal Clipper serial number? I do not see any extra info being garnered from Clipper phones, just less.

Perhaps this is not obvious to others, so I'll be more explicity. If you use a clipper phone at home, the cops can determine your serial number by tapping your line. Then, if you take your phone with you (the little portable AT&T "bump in a cord" is designed for this) everywhere you go you are signaling where you are. Perry