The saga of Hillary Clinton and her emails took an unusual turn on Friday: the State Department announced it is withholding 22 emails because they contain information marked "top secret." And Clinton's campaign immediately objected, putting out a statement demanding that the emails be released.

So what is going on here? Why are these emails top secret, why is it a big deal, and why would Clinton, of all people, want them released?

It's impossible to know the answers to those questions with absolute certainty without seeing the emails. But the key dispute is over whether the classification shows that Clinton was emailing out highly sensitive secrets or if these were everyday emails that just got swept up in America's deeply broken classification system. There's some real reason to believe that the latter is at least possible. Here's what we know and how to parse this latest email controversy.

One really key issue here is when the emails were classified

This might seem unimportant. If it's top secret, then it must be really sensitive, right?

Not necessarily. A large proportion of documents that our government classifies are not actually that sensitive — more on that below. So the key thing now is to try to figure out: Were these emails classified because they contain highly sensitive information that Clinton never should have emailed in the first place, or because they were largely banal but got scooped up in America's often absurd classify-everything practices?

Obviously we can't know the answer to that for sure unless we read the emails. But one good way to make an informed guess is by asking whether the emails were classified at the moment they were sent or whether they were classified only later.

The reason this matters is that if they were immediately classified top secret, then that is a good sign that they contained information that is known as "born classified" — that it was information in itself obtained by classified channels or because it was generated internally by classified means. For example, if Clinton were emailing the secret US bombing plans for Libya, or sharing something that the French ambassador told her in confidence, that would be "born classified."

But if the information were classified only later, then that would indicate it was more banal, or that it was not classified for any reasons particular to the emails themselves. Again, see below on how a boring email could become marked as top secret.

According to a statement by the State Department, "These documents were not marked classified at the time they were sent."

In other words, they do not contain information that was "born classified," but rather fall into the vast gray area of things that do not seem obviously secret at the time but are later deemed that way — not always for good reason.

This might all just be a product of America's problem with overclassification

The American government's system for classifying things as secret is widely considered a giant mess, by which agencies reflexively overclassify things, and the reasons for classifying often make little sense. It is thus extremely easy to imagine that Clinton's emails were classified not because they contained super-sensitive national secrets, and possibly not for any good reason at all, but rather just as a product of America's broken classification system.

This goes back to 1982, when the Reagan administration began a program of such aggressive classification that the unofficial slogan was, "When in doubt, classify." This waned under Bill Clinton but shot back up dramatically under George W. Bush, so much so that by 2004 the mere bureaucracy for classifying documents cost $7 billion per year.

Even John Bolton, a senior Bush official who often championed executive secrecy, once complained, "If there is anyone who fully understands our ‘system’ for protecting classified information, I have yet to meet him."

The problem was not so much secrecy itself as bureaucratic disarray; something that contains no obviously sensitive information might nonetheless be reflexively classified, or might be classified because the information at some point passed through someone or something that also handles classified information. Or maybe the information is banal but it was later wrapped into a report or document that is itself classified for different reasons.

The problem, in other words, isn't that the rules for classification are too strict. It's that the rules are unclear, messy, or contradictory, to the degree that the rules exist at all, and individual people and agencies have learned to overclassify to stay on the safe side.

The problem has grown so severe that it has hampered even the ability of American intelligence officials and policymakers to access the information they need to do their jobs. The head of the 9/11 Commission, Richard Ben-Veniste, told Congress in 2005 that "the failure to share information was the single most important reason why the United States government failed to detect and disrupt the 9/11 plot." He warned, "Information has to flow more freely. Much more information needs to be declassified. A great deal of information should never be classified at all."

In 2010, as a result, Congress passed the Reducing Over-Classification Act, which ordered federal agencies to do exactly that.

But no one thinks that overclassification has been fixed. Federal agencies still have a habit of heavily classifying things, regardless of whether they need to be.

As an example of how silly this can get, State Department employees are banned from reading WikiLeaks cables or articles that quote them, as the cables include classified information. So the people responsible for guiding American foreign policy are barred from reading foreign policy coverage that you and I may access freely. Virtually no one in the State Department likes this policy, by the way, but it is a product of the government's larger, and largely broken, system of assigning and dealing with classifications.

So what does that mean? Do Clinton's emails contain sensitive national secrets?

The unsatisfying truth is that we don't know. The only way to know for sure is to read the emails, and the government is just not very good at declassifying things like this quickly or easily. The Clinton administration had to fight pretty hard to roll back Reagan-era classification practices. Maybe the Obama administration will find a way, if this becomes a problem for Hillary Clinton, but it could also end up hanging over her for months.

Unfortunately this story will be immediately politicized, polarizing people into seeing Clinton as absolutely guilty or absolutely innocent.

The Associated Press got a little carried away in writing this up, declaring that the government had "confirmed" that "Hillary Clinton's unsecured home server contained some of the U.S. government's most closely guarded secrets." Maybe this will turn out to be true, but at present we have no idea that it is, and it strikes me as irresponsible to assert this when anyone who has reported on the government's overclassification addiction knows that classified information is just as likely to be banal as is to be "the US government's most closely guarded secrets."

Rep. Adam Schiff, the ranking Democrat on the House Intelligence Committee, released a statement defending Clinton, saying that he had read many of the emails and urging people to remember that the classification process can be messy, particularly with after-the-fact classification like that applied here. But Schiff has an obvious political interest in seeing Clinton defended here, so take that with a grain of salt.

It makes sense why the Clinton campaign would want these emails released. If they remain top secret, then this will give her Republican opponents an opening to accuse her of bandying highly sensitive secrets around on her private email account, and thus paint her as dangerously irresponsible.

The Clinton campaign's statement is obviously meant to imply that the emails are harmless enough to be immediately released and thus do not contain anything particularly sensitive. But it's also possible this is just a clever bluff.