Consumer Federation of California

Apple said it will equip its new iPhones with a "kill switch" that will render the devices useless if stolen – making the Cupertino firm the first manufacturer to act on a chorus of law enforcement calls to discourage robbers who are targeting smartphones.

The switch will enable a user to deactivate a stolen cell phone via a website. It will prevent a thief from erasing the owner’s data from the phone, even if the SIM card – the integrated circuit that includes an owner’s password and other identifying information – is removed, Apple said.

Once a user throws the kill switch – or activation lock, as Apple calls it – only someone with the registered username and password will be able to unlock it or turn off a homing feature that allows the owner to find it via GPS.

Apple will add kill switches to all its mobile devices, not just iPhones.

"We think this is going to be a really powerful theft deterrent," Craig Federighi, Apple’s senior vice president of software engineering, said at a software designers conference Monday in San Francisco.

Official initiative

The feature will be part of the latest version of operating software due out this fall, Apple said.

The company made the announcement three days before San Francisco District Attorney George Gasc