After AP raid journalists use Snapchat to protect sources, but is it safe?

This morning NPR had a segment about how investigative journalists are becoming increasingly more secretive about their digital correspondence. During the segment Lucy Dalglish, who runs the journalism school at University of Maryland, College Park, and who used to run the Reporters Committee for Freedom of the Press said that,

"If you have a source that you need to protect, stay off the Internet, stay off the phone, don't use your credit card," she explains.
Instead, she says, "talk to your sources like spies do on TV — on a park bench, face to face."

This comes as no surprise after the Department of Justice confiscated two months worth of work, home, and cellphone records from more than 100 Associated Press journalists on Tuesday. The issue at hand is that the Justice Department now has access to phone numbers linked to sources that had a necessity to remain anonymous after disclosing what the DOJ says was "sensitive" national security information. The AP and other American news agencies have, until now, been able to shield their sources under the First Amendment and for the sake of reporting transparently. But recently the AP raid has turned a new stone in the landscape of government reportage, leaving journalists paranoid of being scapegoated as enemies of the state. Pulitzer Prize winner David Cay Johnston said on Democracy Now this week that  Bill Keller, editor of The New York Times, was summoned to the White House office and literally threatened with the death penalty over investigative work The New York Times did. In addition, John Kiriakou, a former CIA analyst, is serving a 30 year sentence in Pennsylvania for giving information to The New York Times 

As result more journalists are turning to Snapchat, an app originally designed for teens to share self-destroying pictures, in order to protect their sources. "The app is no longer for sexting," says one New York Magazine reporter. "A contact last week insisted we only communicate through Snapchat in order to safe guard themselves."