Are you at risk of being cloned? No, we're not referring to the act of another version of "you" being created in some test tube, but rather the practice of wireless phone cloning, which only became a widespread issue over the last couple of decades.
A Primmer on Wireless Cloning
Copying the identity of one mobile telephone to another is called "cloning." The most common purpose of cloning, which is really a form of identity theft, is so someone can place calls under the name (and on the billing account) of the actual subscriber. Cloning has been a common practice with individuals with friends and family who live far away. Through cloning, they could phone home across oceans and continents and save on very expensive calls.
"Bag" phones - personal transportable cell phones made and used in the 1990s - brought about more widespread incidents of cloning, which increased with the advent of "brick" phones later in that decade. The act of cloning involved the perpetrator modifying or replacing the EPROM in the phone with a new chip. The phone's electronic serial numbers (ESN) would be reconfigured via software and both it and the Mobile Identification Number (MIN) would be reprogrammed into a computer chip of another wireless phone. The phone calls made by the cloned phone are listed on the monthly bill of the person whose phone was cloned. The ESN-MIN could be captured over the airwaves and then cloned. The ESN-The carriers have developed authentication features that have greatly reduced cell phone cloning.
It's not Sci-Fi; It's Reality
Of the three types of fraud risks - cloning, theft and subscription fraud - incidences of cloning have actually fallen off quite a bit in recent years, although the other fraud risks have remained high. Not all cloned phones are created for illicit use, however. Some companies provide their employees with wireless phones that are intended strictly for business use. In order to keep their employees from using the phone for personal use, businesses mandate that their employees travel and work with two phones, without regard to how cumbersome that can be. Also, there are Third World nations served by networks operating in limited geographic areas, so the demand in these areas for a single Mobile ID Number can be high.