Nichols was dumb enough to actually be caught in possession of a card used in at last part of the conspiracy. Other cards that seem to be linked to Nichols were used to locate or obtain ANFO and call the rental agency for the Ryder truck as well as other numbers linked to the crime. That is public knowledge at this point. Clearly, logs are available to law enforcement vis-a-vis pre-paid calling cards when they wish to use them. Given the time between the bombing and the capture of at least one of the cards (3-4 days) I suspect those logs are available for at least a few days. Given that the prosecutors claim to be able to link the ANFO purchase via calling cards it is probably a lot longer. What is confusing are the reports that the calling card (or one of them) "bore the name Daryl Bridges." Pre-paid cards don't have names imprinted on them. They would have to have a spot to write them in deliberately. I haven't seen this on any and why would anyone (particularly as part of a criminal conspiracy) do such a thing? Keeping calling cards from leaking information probably isn't possible. Limiting the information leaked to that which is already known or is useless is probably the best bet. Using separate cards for separate operations / cells and immediate disposal seems pretty critical. Note something else, however. I haven't heard of any instances of real time calling card interception. One was described here on the list but that presupposes that a degree of surveillance already exists around the subject. All bets are pretty much off in that event. Calling cards are "after the fact" evidence, not preventative evidence.
-----Original Message----- From: owner-cypherpunks@minder.net [mailto:owner-cypherpunks@minder.net] On Behalf Of R. A. Hettinga Sent: Friday, March 26, 2004 7:10 PM To: Thomas Shaddack; Cypherpunks Subject: Re: Anonymity of prepaid phone chip-cards
I strongly suspect the usage logs exist for individual cards, allowing to back-trace the phonecalls done with the given card, thus
At 7:51 PM +0100 3/26/04, Thomas Shaddack wrote: tracing the
identity of the card's owner by the call patterns.
Of course.
How do you think they caught the Oklahoma City bombers?