Only JMP uses them, and I would guess the responsible people work as subbies for JMP, and are teaching the criminal buddies they have as to how easy it is to get a free short use SIM. Makes you wonder why the cell supplier did not lock the SIM's to have at least a closed group of numbers at least, it has been available from day one, though I would guess it never crossed the minds of JMP that these are open SIM's, and did not lock them to be GPRS data only, and to give them a special gateway to communicate though, as this is part of the GSM specs and would make them unusable. Best guess is the network operator did not do so as they get paid irrespective of the card being stolen, unless the Metro demands a refund of the fraudulent calls, then suddenly all these SIM's will magically get locked down overnight.
The copper thieves are getting out of hand, They will steal 20c of copper from anything, and steal aircons that are accessible for the copper, and even steal plastic piping that has brass inserts in the joins for the metal.
What would help is to make the scrap dealers that buy this pay for the replacement and repairs if stolen material is found, not just a fine and business as usual.