After months of denials and delaying actions, Hillary Clinton has decided to turn over her private email server to the Department of Justice. As this controversy has grown since the spring, Clinton and her campaign operatives have repeatedly denied that she had placed classified information in her personal email while serving as secretary of state during President Obama’s first term. (“I am confident that I never sent nor received any information that was classified at the time it was sent and received,” she said last month.) Her team also denied that she would ever hand over her server to investigators. Now both those assertions have been overturned.

Hillary Clinton has little choice but to hand over her server to authorities since it now appears increasingly likely that someone on her staff violated federal laws regarding the handling of classified materials. On August 11, after extensive investigation, the intelligence community’s inspector general reported to Congress that it had found several violations of security policy in Clinton’s personal emails.

Most seriously, the inspector general assessed that Clinton’s emails included information that was highly classified—yet mislabeled as unclassified. Worse, the information in question should have been classified up to the level of “TOP SECRET//SI//TK//NOFORN,” according to the inspector general’s report.

You may have seen acronym lists like these on declassified documents before—and glazed over them. This is the arcane language of the cleared cognoscenti, so let me explain what this means:

• TOP SECRET, as the name implies, is the highest official classification level in the U.S. government, defined as information whose unauthorized release “could cause exceptionally grave damage to national security or foreign relations.”

• SI refers to Special Intelligence, meaning it is information derived from intercepted communications, which is the business of the National Security Agency, America’s single biggest source of intelligence. They’re the guys who eavesdrop on phone calls, map who’s calling whom, and comb through emails. SI is a subset of what the intelligence community calls Sensitive Compartmented Information, or SCI. And these materials always require special handling and protection. They are to be kept in a Sensitive Compartmented Information Facility, or SCIF, which is a special hardened room that is safe from both physical and electronic intrusion.

• TK refers to Talent Keyhole, which is an intelligence community caveat indicating that the classified material was obtained via satellite.

• NOFORN, as the name implies, means that the materials can only be shown to Americans, not to foreigners.

In short: Information at the “TOP SECRET//SI//TK//NOFORN” level is considered exceptionally highly classified and must be handled with great care under penalty of serious consequences for mishandling. Every person who is cleared and “read on” for access to such information signs reams of paperwork and receives detailed training about how it is to be handled, no exceptions—and what the consequences will be if the rules are not followed.

In the real world, people with high-level clearances are severely punished for willfully violating such rules. At a minimum, those suspected of mishandling things like NSA “signals intelligence”—intercepts calls, emails, and the like—have their clearances suspended pending the outcome of the investigation into their misconduct. Any personal items—computers, electronics—where federal investigators suspect the classified material wound up, wrongly, will be impounded and searched. If it has TOP SECRET//SI information on it, “your” computer now belongs to the government, because it is considered classified.

People found to have willfully mishandled such highly classified information often face severe punishment. Termination of employment, hefty fines, even imprisonment can result. Yes, people really do go to jail for mishandling classified materials. Matthew Aid, a writer on intelligence matters, served more than a year in prison for mishandling TOP SECRET//SI information from the NSA, for example. The well-connected tend to avoid jail, however. Sandy Berger and John Deutsch—who both served in high-level positions under President Bill Clinton, did not go to prison for mishandling TOP SECRET intelligence (though Berger got probation and was fined $50,000).

What, then, does all this mean for Hillary Clinton? There is no doubt that she, or someone on her State Department staff, violated federal law by putting TOP SECRET//SI information on an unclassified system. That it was Hillary’s private, offsite server makes the case even worse from a security viewpoint. Claims that they “didn’t know” such information was highly classified do not hold water and are irrelevant. It strains belief that anybody with clearances didn’t recognize that NSA information, which is loaded with classification markings, was signals intelligence, or SIGINT. It’s possible that the classified information found in Clinton’s email trove wasn’t marked as such. But if that classification notice was omitted, it wasn’t the U.S. intelligence community that took such markings away. Moreover, anybody holding security clearances has already assumed the responsibility for handling it properly.

As secretary of state, Hillary Clinton had no authority to disseminate intelligence-community information on her own, neither could she make it less highly classified (a process termed “downgrading” in the spy trade) without asking permission first.

It is a very big deal and less-connected people who do this sort of thing ruin their lives, as any IC counterintelligence official can attest. During my NSA time, I saw junior personnel terminated for relatively minor infractions of security regulations. While the U.S. government unquestionably does over-classify items on the policy side, where almost everything in the Defense and State Departments gets some sort of classification stamp, not usually at a high level, intelligence reporting by its very nature is classified. If you don’t want the responsibility of a high-level government position, which inevitably brings with it TOP SECRET//SI access, then don’t accept that burden.

There’s still a lot we don’t know about Hillary Clinton’s Emailgate. Exactly how many emails contained TOP SECRET//SI information is unclear. We may never know since thousands of emails were already destroyed by Clinton. Who exactly placed the classified information in emails—it may not have been Hillary Clinton—and how did they access the information in the first place? How many of her staffers at Foggy Bottom were also using her personal server?

Underlying all this is the question of why Hillary Clinton decided to employ her own private email and server to handle so much of her official State Department business. This is, to say the least, highly irregular—not to mention a violation of numerous U.S. government rules and regulations—so there had to be a compelling reason to do this. What was it?

The Clinton campaign was concerned enough about the issue to send out an email blast Wednesday afternoon with the subject line: “A note about Hillary Clinton’s emails.”

“You might hear some news over the next few days about Hillary Clinton’s emails,” began the email from Jennifer Palmieri, the communications director for Hillary for America.

“Because you are an important part of this team, we wanted to take a few minutes to talk through the facts—we need your help to make sure they get out there. There’s a lot of misinformation, so bear with us; the truth matters on this.”

Underneath the greeting were several bolded bullet points, including, “Hillary didn’t send any classified materials over email.” There was also a link to a longer, 4,000+ word explanation of why Clinton used a private email address and server in her official capacity as secretary of state.

The FBI is now on the case and one hopes they will exercise due diligence in their investigation of what may be a serious leak of classified information, made worse by the fact that Clinton’s personal server was wholly unencrypted for three months, leaving it wide open to exploitation by foreign intelligence services.

The number of spy services interested in the communications of the U.S. secretary of state numbers more than a hundred. Given their technical proficiency, it’s naïve to assume that the Russians and Chinese aren’t among them—a fact that John Kerry, the current secretary, recently admitted.

It’s safe to assume, then, that Moscow and Beijing know what Hillary’s “private” emails as Secretary of State contained. Let’s hope that the American public will someday as well.