 Modifying these, as well as the phone's Preferred Roaming List (PRL) and the mobile identification number, or MIN, can pave the way for fraudulent calls, as the target telephone is now a clone of the telephone from which the original ESN and MIN data were obtained.Cloning has been shown to be successful on CDMA, but rare on GSM.However, cloning of a GSM phone is achieved by cloning the SIM card contained within, but not necessarily any of the phone's internal data.