Two prominent newspapers this week used their editorial pages to call for mercy for intelligence leaker Edward Snowden, with one arguing "he deserves better than a life of permanent exile, fear and flight." 

The New York Times and The Guardian make the case for some sort of plea deal or clemency that would allow Snowden to return to the United States from Russia, where he was granted asylum. 

Mercy or dropped charges have occurred in past cases of other high-profile whistle-blowers, such as Daniel Ellsberg, the military analyst behind the leak of the Pentagon Papers. But in recent years, the United States has aggressively pursued those who leak government secrets. 

Here's a look at how the cases of five prominent leakers -- including Snowden -- have played out: 

Daniel Ellsberg 

Ellsberg was the military analyst who leaked the 7,000-page Pentagon Papers in 1971. 

The top-secret documents revealed that senior U.S. leaders, including three Presidents, knew the Vietnam War was an unwinnable, tragic quagmire. Further, they showed the government had lied to Congress and the public about the progress of the war. 

Ellsberg surrendered to authorities and was charged as a spy. 

During his trial, the court learned that President Richard Nixon's administration had embarked on a campaign to discredit Ellsberg, illegally wiretapping him and breaking into his psychiatrist's office. All charges against him were dropped. Since then, he has lived a relatively quiet life as a respected author and lecturer. 

Chelsea Manning 

U.S. Army Pvt. Chelsea Manning, who formerly went by the name Bradley, was convicted of stealing and disseminating 750,000 pages of classified documents and videos to WikiLeaks, the online anti-secrecy group.  QUESTIONS:

Q1:
1. What is the identity of Daniel Ellsberg?
2. What is Daniel Ellsberg known for?
3. What is notable about Daniel Ellsberg?
Q2:
1. What did the Pentagon Papers reveal?
2. What was leaked in the Pentagon Papers?
3. What did the Pentagon Papers teach the public?
Q3:
1. When were the Pentagon Papers leaked?
2. When did the release of the Pentagon Papers occur?
3. In what year were the Pentagon Papers released?
Q4:
1. What did Nixon do to Daniel Ellsberg?
2. How did Richard Nixon try and discredit Daniel Ellsberg?
3. What action did Richard Nixon take against Daniel Ellsberg?
Q5:
1. What did Nixon do to Daniel Ellsberg?
2. How did Richard Nixon try and discredit Daniel Ellsberg?
3. What action did Richard Nixon take against Daniel Ellsberg?
Q6:
1. Was Daniel Ellsberg thrown in jail?
2. Did Daniel Ellsberg spend time in jail?
3. Was Daniel Ellsberg jailed?
Q7:
1. What kept Daniel Ellsberg out of prison?
2. Why wasn't Daniel Ellsberg sent to prison?
3. Why didn't Daniel Ellsberg go to jail?
Q8:
1. What happened to the charges against Daniel Ellsberg?
2. What became of the charges against Daniel Ellsberg?
3. What was ultimately done with the allegations against Daniel Ellsberg?
Q9:
1. Where does Edward Snowden live these days?
2. What is Edward Snowden's current place of residence?
3. Where does Edward Snowden presently reside?
Q10:
1. Why is Edward Snowden living in Russia?
2. What is Edward Snowden's reason for taking up residency in Russia?
3. What made Edward Snowden decide to live in Russia?
Q11:
1. Who is calling for clemency for Edward Snowden?
2. Who wants the government to have mercy on Edward Snowden?
3. Who is making the case for a plea deal for Edward Snowden?
