Originally Posted by TroyDBrown
Can it be done yes, 100%
Why you do not want to:
1. The cloned card may produce errors to the network and get failed calls.
2. The cellular network uses electronic digital fingerprints that can tell if it is a different SIM. (Fraud Detection)
3. If the SIMS by any chance were both active at the same time your account is locked and you have some explaining to do.
At one point if AT&T/Cingular/at&t caught you with a cloned SIM they would cancel your account charge you an ETF. If one carrier is doing it, expect the others to follow suit. Just another 175 reasons NOT to even try it.