Gordon Burditt wrote:

The longer the range and the more related to money it is, the more
abusable it is. IMEI numbers are pretty long-range (I suspect
providers can do a network-wide international search, although the
radio signal probably reaches only a few nearby cell towers) for
tracking but don't seem to have much potential for financial abuse.
(At least on T-Mobile, the SIM card, not the IMEI, seems to provide
the billing info).

Serial numbers are useful to people who steal phones. There is a worldwide
database of lost (greylist) and stolen (blacklist) GSM phones. It can
only be updated by a service provider and they can choose to use it
or ignore it.

Back in the final days of the last century, the UK cellular carriers
did not use the data base to encourage people to buy pay as you go SIMs
and put them in stolen phones. In those days they were planning IPOs, and
the valuation of the company was based upon the number of subscribers
(active SIMs) and not revenue.

Since GSM phones were new here (in Israel) and very expensive, I purchased
several used phones from a dealer in the UK who took them in trade, tested
them and sold them over the internet. When they arrived here, they
were blacklisted. Israel Orange used the blacklist.

To be honest, I'm not sure anyone cares though. There was a version of the
software to unlock the old Nokia handsets via a computer cable, and every time
you ran it, it incremented the phone's IEMI by one. I assume because there
were so many stolen phones that it was necessary. :-)

Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379