Law enforcement officials say Apple's addition of a kill switch is the reason smart phone crimes are down.  

The "New York Times" says iPhone robberies fell by almost 40 percent in San Francisco after the phone lock feature was introduced.  

San Francisco District Attorney George Gascón has been one of the most vocal supporters of a kill switch and started a Secure Our Smartphones initiative with the DA of New York.  

Microsoft and Google both say they will be introducing a kill switch in future software updates.