There's been a blizzard of news about the Obama administration's crackdown on government officials who leak classified information to the media. Last week we learned that the government seized the phone records of more than 100 Associated Press journalists. This week we learned that the government had accused (though not charged) journalist James Rosen with a crime for accepting classified information from a source, and that the government also obtained phone records for Rosen's parents.

The revelations are coming so fast that it's hard to keep the characters, cases and issues straight. We're here to help. Read on for everything you need to know about the government's war on leakers.

Some people say the Obama administration's campaign of leak prosecutions is unprecedented. Is that true?

Just about. Before Obama took office, the federal government had only invoked the 1917 Espionage Act against three people for leaking classified information to the media. And only one of those, Samuel Loring Morison, was convicted. The rap against him was that leaked classified photographs of Soviet warships to the British publication Jane's Defense Weekly in the 1980s.

In the early 1970s, the government tried to prosecute Daniel Ellsberg and Anthony Russo for leaking the Pentagon Papers, a classified government report that candidly acknowledged how poorly the Vietnam War was going. The charges were dropped after the judge in the case learned that the government had subjected the defendants to illegal surveillance.

Since Barack Obama took office for the first time, the Justice Department has indicted six individuals for leaking information to the media, twice as many as all previous administrations combined.

Who has the Obama administration charged?

Shamai Leibowitz was charged in 2009 with leaking transcripts produced from surveillance of Israeli diplomats. He was concerned the transcripts showed that Israeli and U.S. authorities were engaged in a "perception management" campaign about Iran that could lead to military conflict. He was sentenced to 20 months in prison in 2010.

Thomas Drake was an employee of the National Security Agency who was indicted in 2010 after he spoke to a Baltimore Sun reporter about a NSA surveillance program that he believed violated Americans' privacy and wasted taxpayer money. The government's case against him fell apart. The judge called the prosecution "ill-considered."

Bradley Manning was an American soldier who was arrested in 2010 for passing thousands of classified documents to WikiLeaks. Manning hoped to spark a national debate about the morality of U.S. conduct in the Iraq war. He pleaded guilty to several charges in February and could spend decades in prison.

Stephen Kim was indicted in 2010 after he told Fox News reporter James Rosen that if the United Nations imposed new sanctions on North Korea, it would respond by conducting nuclear tests. His case is ongoing.

Jeffrey Sterling was a CIA employee who was indicted in 2010 for leaking information to the media about a CIA project to sabotage the Iranian nuclear program. His case is ongoing.

John Kiriakou was a CIA employee who was indicted in 2012. He was the first U.S. official to speak publicly about the U.S. waterboarding program, which he criticized as torture. He pleaded guilty and was sentenced to 30 months in prison in January.

Why has the Obama administration prosecuted so many leak cases?

Only senior administration officials know for sure. But Scott Shane, one of the journalists who talked to Kiriakou, said he believes that the crackdown wasn't a deliberate policy of the president or Attorney General Eric Holder. Rather, Shane believes that the prosecutions were initiated by individual prosecutors in various parts of the Obama administration. Holder could have blocked the prosecutions but chose not to.

There's a technological element here, too. Catching and convicting leakers has gotten easier because more and more information, from e-mails to credit card transactions, is being captured in electronic form. That gives the government more ways to identify and convict leakers.

These prosecutions have been under way for years. Why is the media suddenly interested in the topic?

Two recent developments have gotten journalists to pay attention. First, last week the Associated Press learned that the government had obtained weeks of phone records from more than 100 AP reporters.

Then, on Monday The Washington Post revealed a search warrant for the e-mail account of Fox News reporter James Rosen. The government's request, filed in 2010, suggested that by accepting classified information from Stephen Kim, Rosen himself may have acted as an "aider and abbetor and/or co-conspirator" in Kim's crime.

Critics have long warned that the cracking down on leakers was damaging to the freedom of the media. But seeing the government suggest that it's a crime for a journalist to accept classified information from a source has grabbed the media's attention.

The government says leaks damage national security. Is that true?

It's hard to know, since many of the details in these cases are still classified. But the AP case, at least, seems to be an example of where the leak had harmful consequences.

That investigation concerns an American operative who had successfully infiltrated a terrorist cell in Yemen. He told the terrorist cell he wanted to blow up an American airplane and was given an underwear bomb for this purpose.

His plan was to turn the bomb over to his American handlers and then tell his terrorist contacts that the bomb had failed to go off. That would have allowed him to continue providing intelligence to the U.S. government. But the AP caught wind of the plot and reported that it had been foiled by the United States.

The AP didn't reveal (and may not have known) that the man was actually a U.S. agent. But government sources told the L.A. Times that the report led to the man's cover being blown.

The AP says it delayed publication of its story until it was advised that it no longer posed a national security risk.

Isn't the government just doing its job? Leaking classified information is illegal, right?

No one objects to prosecuting spies who send classified information to foreign governments. But civil libertarians emphasize that leaks to the media play a critical role in the democratic process. The public can't make informed decisions in the voting booth if it doesn't know what the government is doing.

And governments face a powerful temptation to over-classify in order to prevent the release of information that might be embarrassing to those in power. The Pentagon Papers, a frank admission that the Vietnam War was going poorly, is a classic example. Drake's leaks about wasteful spending by the NSA, are another. In both cases, the national security consequences of the leaks seem minor, but they provided policymakers and voters with important information.

Leaks to the media provide an important check on the government's classification power. If the government had absolute control over the public's access to information about the security state, it would be too easy for the government to hide information about lawbreaking, incompetence and corruption by government officials.

What happens next?

We know of several cases that are ongoing, including the Manning, Sterling, and Kim prosecutions and the AP investigation. The recent controversy does not seem to have deterred the administration from continuing to pursue those cases.

The White House responded to last week's AP revelations by urging Congress to pass the Free Flow of Information Act, a law that would formally shield journalists from liability for reporting leaked information. The proposal died in the Senate early in Obama's first term.