Americans accused of divulging secrets to the media have escaped long prison sentences, a pattern that may reassure Edward Snowden, the former NSA contractor who exposed the U.S. government's top-secret surveillance programs last week.
In the nine such criminal cases in U.S. history, two people served no prison time, one person was sentenced to 10 months in a halfway house and three defendants received sentences of about two years. Three cases are unresolved, including that of U.S. soldier Bradley Manning, the accused source of secret files given to anti-secrecy website WikiLeaks.
The sentences show the limited punishment that U.S. prosecutors have been able to elicit when an American is accused of passing confidential information to journalists.
Six of the nine cases have been brought since President Barack Obama took office in 2009, reflecting a government-wide crackdown on unauthorized leaks.
Snowden, 29, said he is planning to seek asylum after he admitted providing secret documents to Britain's Guardian newspaper and the Washington Post showing the extent of phone and internet monitoring programs at the U.S. National Security Agency.
He told the Guardian that he accepts the risk of prison but does not think he deserves punishment. "I don't think I have committed a crime outside the domain of the U.S. I think it will be clearly shown to be political in nature," he said.
Snowden moved to Hong Kong last month and said he was exploring seeking asylum in Iceland or elsewhere.
"I do not expect to see home again, though that is what I want," he told the Guardian.
The U.S. Justice Department said it had opened a criminal investigation into the unauthorized disclosure of classified information by a person with authorized access.
Department spokeswoman Nanda Chitre said the investigation was in its initial stages. Asked whether prosecutors had made a determination that a crime had been committed by leaking the information to the newspapers, she declined to comment.
U.S. Representative Mike Rogers, the Republican chairman of the House Intelligence Committee, said in a statement that any leaker "should be punished to the fullest extent of the law."
The law in question, part of the Espionage Act originally enacted in 1917, carries a maximum sentence of 10 years in prison for each criminal count.
"In no case has the maximum penalty been imposed," said Steven Aftergood, the director of the Project on Government Secrecy for the Federation of American Scientists.
Aftergood, who argues for government transparency, said that was because leak cases have complicated facts and the laws are ambiguous. Prosecutors also are reluctant to take a case to trial for fear of disclosing more classified material.
Use of the law to prosecute leaks to the press is murky because there are so few examples, said Elizabeth Goitein, a national security expert with the Brennan Center for Justice at New York University.
"We don't have a great model," she said.
Prosecutors used the law in 1971 to charge Daniel Ellsberg, a national security analyst who passed defense documents known as the Pentagon Papers to The New York Times. A judge dismissed the case on evidence that the government had wiretapped Ellsberg, possibly illegally.
Lawrence Franklin, a former U.S. Defense Department employee who pleaded guilty in 2005 to giving classified information about Iran to pro-Israel lobbyists, initially was sentenced to more than 12 years in prison.
But after the government's case against the lobbyists fell apart, U.S. District Judge T.S. Ellis reconsidered and imposed a new sentence of 10 months in a halfway house.
Former CIA officer John Kiriakou is serving the longest prison sentence, two and a half years, of the nine people indicted for telling secrets to the media. However, in a plea agreement with prosecutors, he was convicted under a different law for disclosing the identity of a covert agent.
Manning, whose military trial at Fort Meade, Maryland, is ongoing, already faces up to 20 years in prison because he pleaded guilty in February to 10 lesser charges that he misused classified information.
Many of the defendants in leak cases avoided long prison terms after hiring high-priced Washington lawyers and enduring long court battles. It was unknown whether Snowden had a lawyer.
"The only friends he had up until today were the journalists around about him, but that's changed now. I can't say anything more," Guardian journalist Ewen MacAskill in Hong Kong told Reuters.
MacAskill and other journalists who received information from Snowden should be able to breathe easier than him.
U.S. Attorney General Eric Holder told a congressional committee on Thursday, the day after the Guardian began publishing its scoops, that as long as he is in charge of the Justice Department, it "will not prosecute any reporter for doing his or her job."
The United States also has little ability to stop the media from publishing any more classified material.
In a pillar of American press freedom, the U.S. Supreme Court in 1971 rejected President Richard Nixon's attempt to stop publication of the Pentagon Papers and greatly restricted the government's power to censor the media.