NSA task force leader backs talks on amnesty for Snowden

The head of the National Security Agency task force assessing the effect of leaks by former NSA contractor Edward Snowden opened the door to the possibility of offering Snowden amnesty in exchange for documents -- though his boss is not on board with the idea.

In an interview with CBS' "60 Minutes," Rick Ledgett said that Snowden took "the keys to the kingdom" when he left the U.S. earlier this year and was granted temporary asylum in Russia.

He said he supports at least having a discussion about offering Snowden amnesty from criminal charges if he returns sensitive files still in his possession, and claimed others at the NSA share that view.

"My personal view is, yes, it's worth having a conversation about," Ledgett said. "I would need assurances that the remainder of the data could be secured and my bar for those assurances would be very high. It would be more than just an assertion on his part."

However, NSA Director Gen. Keith Alexander sharply disagreed. He likened it to "a hostage taker taking 50 people hostage, shooting 10 and then say 'You give me full amnesty and I'll let the other 40 go.'"

"I think people have to be held accountable for their actions," Alexander said. "Because what we don't want is the next person to do the same thing, race off to Hong Kong and to Moscow with another set of data knowing they can strike the same deal."

The White House on Monday re-enforced that stance.

"Our position hasn't changed on that matter at all," Press Secretary Jay Carney said. "What I can tell you is Snowden has been accused of leaking classified information and faces felony charges in the U.S. He should be returned to the U.S. as soon as possible where he'll be afforded due process and protections."

Ledgett also told CBS correspondent John Miller, himself a former employee of the office of the Director of National Intelligence, that he would not dispute an estimation that Snowden had taken 1.7 million documents from the NSA's hard drives, using his security clearance to get around measures that blocked off access for typical employees.

"He did something that we call scraping," Ledgett said. "Where he went out and just went-- used tools to scrape information from websites, and put it into a place where he could download it."

Ledgett said that Snowden had taken "an exhaustive list of the requirements that have been levied against-- against the National Security Agency. And what that gives is, what topics we're interested in, where our gaps are. But additional information about U.S. capabilities and U.S. gaps is provided as part of that."

Ledgett estimated that 31,000 of the documents taken by Snowden dealt with U.S. intelligence capabilities and gaps related to countries like China, Russia, and Iran.

A series of articles published by The Washington Post and by journalist Glenn Greenwald based on documents leaked by Snowden have brought the NSA's practice of collecting phone records and monitoring Internet use by millions around the world under public scrutiny. The NSA has consistently defended its practices as legal.

Alexander strongly denied to "60 Minutes" that the NSA could monitor the communications of any American at any time.

"NSA can only target the communications of a U.S. person with a probable cause finding under specific court order," Alexander said. "Today, we have less than 60 authorizations on specific persons to do that."

Alexander also defended the agency's practice of collecting so-called "metadata" on various phone calls, including the number dialed, time, date, and frequency.

"How do you know when the bad guy who's using those same communications that my daughters use, is in the United States trying to do something bad?" Alexander asked. "The least intrusive way of doing that is metadata.

"The 'to/from' number, the duration of the call and date/time, that's all you get," Alexander said later in the interview. "And all we can do is tell the FBI, 'That number is talking to somebody who is very bad, you ought to go look at it.'"