Are impenetrable phones a threat to national security?

WASHINGTON -- Apple has been unveiling a new generation of devices with bigger screens, sharper cameras and faster processors, but it's Apple's new privacy protections that worry law enforcement.

The latest operating system from the tech giant - and competing software from Google - allow people to permanently lock their smartphones. Only the user knows the security code. Apple and Google say they can't break that code. Neither can police, even with a court order.

FBI Director James Comey warned Thursday this could allow criminals and terrorists to permanently hide their files.

"It's the equivalent of a closet that can't be opened, a safe deposit box that can't be opened, a safe that can't ever be cracked," Comey said.

The new privacy features come in response to a public backlash against broad government surveillance revealed by NSA leaker Edward Snowden.

In marketing its new system, Apple openly boasts about unbreakable encryption, saying: "We wouldn't be able to comply with a wiretap order even if we wanted to."

And in a more direct response to the FBI warning, Google issued a statement, saying: "People previously used safes and combination locks to keep their information secure - now they use encryption."

But Comey said this is about more than protecting the rights of the phone user.

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"I suggest to you that homicide cases could be stalled, suspects walked free, child exploitation not discovered and prosecuted," he said. "Justice may be denied because of a locked phone or an encrypted device."

Comey's asking smartphone manufacturers to take a step back and change course.

But Apple and Google are complying with current law, and they say they're simply responding to the public's demand for better privacy protections.