Don't worry. I don't think you're doing anything wrong. I put my last comment on there for the benefit of anyone
else reading this who may not have a good motive.
Other countries & companies may have different procedures (I worked for AT&T in the US), but if the owner stored
phone numbers to the sim rather than the phone and unless the SIMs are wiped, either by
the company or the end-user, the sim acts basically like a memory card. No subscriber info remains on it,
unless they put some info in the contact list in sim memory, like their home phone, work phone, etc.
Sim memory doesn't support multiple listings for one contact, as the phone does; for example:
under "Fred Smith" you'd list "home 5551212" "work 5551234" "cell 5556789". But if you tried copying this contact to the sim,
only the first listing, in this case "Fred Smith - (home) would be copied. The rest would be lost.
If knew who a customer was, I would give them their old sim back so that they could copy their phone
numbers to their new phone. Otherwise, i would snap the card in the middle before discarding, thus making it unusable.
Not to be political BUT "yes" - nearly all US phone companies, landline & wireless, including AT&T
cooperated with domestic spying. By making subscriber info & access to communications available
without the knowledge or consent of the subscriber.
They were charged, but of course, all charges were dropped.
EDIT: I'm sorry - RIM stands for Research In Motion, the parent company of Blackberry.