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.

"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.