The FBI’s Hillary Clinton email investigation report contains numerous bombshells that show just how careless the former secretary of state was in maintaining and using a private email system while in office.

Here are 23 of the most surprising findings from the 47-page report, which was released on Friday, at the beginning of Labor Day weekend.

Didn’t know that ‘C’ meant ‘Confidential’

The former secretary of state told the FBI during her July 2 interview that she did not know what a “C” marking in one of her emails signified. The letter indicated that the email contained information classified as confidential, but Clinton said she thought it indicated that the paragraphs were in alphabetical order.

“When asked what the parenthetical ‘C’ meant before a paragraph within the captioned email, CLINTON stated she did not know and could only speculate it was referencing paragraphs marked in alphabetical order. CLINTON could not say for sure if the parenthetical ‘C’ is used for portion marking classified documents,” the FBI’s notes say.

The existence of the email undermines Clinton’s past claims that none of the emails she sent or received had classification markings in them. (RELATED: Hillary Didn’t Know Giant Letter ‘C’ In Emails Meant ‘Classified’)

Couldn’t remember briefings after she sustained a concussion

Clinton told the FBI that she was unable to recall some briefings at the State Department after she sustained a concussion and blood clot in Dec. 2012 after a fall. Clinton made the claim when asked whether she was debriefed and told that she was supposed to return her work-related records to the State Department before her departure in Feb. 2013. (RELATED: Clinton Couldn’t Remember State Dept. Briefings After Her Concussion)

“Based on her doctor’s advice, she could only work at State for a few hours a day and could not recall every briefing she received,” the report reads.

Warned to ‘be very careful’ about using private BlackBerry

Retired Gen. Colin Powell warned Clinton in an email exchange on Jan. 23, 2009, two days after Clinton took office, about the ramifications of using a BlackBerry and personal email account.

Clinton emailed Powell, who served as secretary of state under George W. Bush, to ask about his BlackBerry use. Powell responded, warning “that if it became ‘public’ that Clinton had a BlackBerry, and she used it to ‘do business,’ her emails could become ‘official record[s] and subject to the law,'” the report states.

The exhange suggests that Powell conveyed to Clinton that she should keep her BlackBerry and email use secret.

“Be very careful,” Powell advised Clinton in the email. “I got around it all by not saying much and not using systems that captured the data.”

Clinton told the FBI that Powell’s email did not sway her decision about using a private BlackBerry and private email account. But the exchange shows that Clinton knew that keeping the system secret would allow her to avoid complying for laws governing the maintenance of federal records. (RELATED: Hillary Clinton Was Warned To ‘Be Very Careful’ About Using BlackBerry And Personal Email)

Hammer time

Justin Cooper, a Bill Clinton aide who also helped manage Hillary Clinton’s email server, told the FBI that on at least two occasions he destroyed the then-secretary of state’s BlackBerries. (RELATED: FBI Docs: Aide Destroyed Hillary’s Old Phones With A Hammer)

He did so by “breaking them in half or hitting them with a hammer,” according to FBI notes.

‘Could not recall’

During her three-and-a-half our FBI interview, Clinton “could not recall” answers to 40 separate questions.

Clinton’s lawyers invoked attorney-client privilege

David Kendall, Cheryl Mills, and Heather Samuelson, all three members of Clinton’s legal team, declined to give investigators a list of keywords and email addresses they used to guide their search of Clinton’s emails for any work-related material.

The team began searching Clinton’s emails for any work product in Fall 2014.

In a footnote in its report, the FBI said it was unable to obtain that information because of the Clinton lawyers’ “assertion of privilege.”

Clinton kept BlackBerry in off-limits area

Mobile devices were prohibited in the executive suites at the State Department, but that didn’t stop Clinton from keeping her BlackBerry in an off-limits area.

Three State Department Diplomatic Security agents told the FBI that Clinton stored her BlackBerry in “Port 1” of the executive suites, known as Mahogany Row. But Mahogany Row is designated as a Sensitive Compartmented Information Facility (SCIF), and mobile devices are not allowed there because of concerns that they can be used to record and transmit classified information.

Clinton emailed Obama while she was overseas

The FBI found that Clinton emailed with President Obama while she was on overseas trips. And because she used a private BlackBerry, she likely made her communications more vulnerable to being compromised by sophisticated foreign hackers. (RELATED: Clinton Ignored Cybersecurity Threats, Put Obama At Risk Of Being Hacked)

“On [redacted] occasions while OCONUS (Outside Continental U.S.), Clinton had direct e-mail contact with an e-mail address for President Barack Obama,” the report reads. “Of the [redacted] e-mails between Clinton and President Obama, [redacted] were sent and received [redacted].”

FBI unable to find and analyze 13 mobile devices Clinton used

Clinton used at least 13 mobile devices for communications, eight during her State Department tenure.

“As a result, the FBI was unable to acquire or forensically examine any of these 13 mobile devices,” the report states. (RELATED: FBI: We Can’t Locate More Than A Dozen Hillary Devices)

Huma Abedin suggested creating the email system

The report states that it was Huma Abedin, Clinton’s State Department deputy chief of staff, who proposed the idea of having Bryan Pagliano, an information technology official on Clinton’s 2008 presidential campaign, set up a new email system for Clinton at the State Department.

“At the recommendation of Huma Abedin, Clinton’s longtime aide and later Deputy Chief of Staff at State, in or around fall 2008, [Bill Clinton aide Justin Cooper] contacted Bryan Pagliano…to build the new server system and to assist Cooper with the administration of the new server system,” the report states.

Sidney Blumenthal provided info that ‘was sometimes accurate, sometimes not’

Clinton was asked about her emails with her longtime friend, Sidney Blumenthal. The former journalist frequently sent Clinton information he gleaned from a deep network of former government intelligence agents.

Clinton said she did not invite Blumenthal to send her information, some of which was classified. She said she viewed the information Blumenthal sent her “as journalistic because Blumenthal did not have a clearance and was not in government at that time.”

Clinton had wanted to find a job for Blumenthal at her State Department in 2009 but the Obama White House blocked the idea.

Tor

An email account on Clinton’s private server network was successfully infiltrated by someone using an encrypted privacy tool called Tor.

According to the FBI’s report, three IP addresses that matched Tor exit nodes accessed an email account maintained on Clinton’s server. The name of the user is redacted in the report but is believed to be one of Bill Clinton’s female staffers.

The breach is the first documented successful hack of an email account so closely associated with Hillary Clinton’s.

Porn email caused hacking concern

Clinton was worried that someone was attempting to hack into her email account after she received a suspicious message “containing pornographic material,” Huma Abedin told the FBI.

The report states that there is no other information about why Clinton was worried about the email or if it infected Clinton’s account.

Emails deleted after New York Times expose

Some of Clinton’s emails were deleted after The New York Times published its bombshell March 2015 report exposing Clinton’s exclusive use of a personal email account.

Speaking to the FBI on May 3, 2016, a person whose name is redacted in the FBI report “indicated he believed he had an ‘oh shit’ moment and sometime between March 25-31, 2015 deleted the Clinton archive mailbox from the PRN server and used BleachBit to delete the exported .PST files he had created on the server system containing Clinton’s e-mails.”

PRN stands for Platte River Networks, the company Clinton hired to manage her email system after leaving the State Department. BleachBit is an open source piece of software that “digitally shreds” emails.

Top secret rooms at Clinton’s homes weren’t secure

Huma Abedin and Monica Hanley, another Clinton aide, told the FBI that the SCIFs at both of Clinton’s homes, the one in Washington, D.C. and the one in Chappaqua, N.Y., were not always locked and secured. (RELATED: FBI: Top Secret Rooms At Clinton’s Homes Were Not Always Secure)

“According to [Clinton’s State Department deputy chief of staff Huma Abedin], the SCIF door at the Whitehaven residence was not always locked, and Abedin, [Clinton aide Monica Hanley], and [redacted] had access to the SCIF,” the report reads.

Conflicting statements to FBI

Clinton told the FBI that personal computers were never set up in the SCIFs at her homes. But Huma Abedin, Justin Cooper and another individual gave contradictory statements. They said that they did recall seeing personal computers in those secured rooms.

Pagliano was told classified info would traverse server

Clinton’s IT guru told the FBI that he was advised in early 2009 by a person who went unnamed in the bureau’s report that they would not be surprised if classified information would traverse Clinton’s server.

Despite that knowledge, Pagliano appears to have done nothing to inform others at the State Department. He took a job there as an IT adviser in May 2009. He was hired as a political appointee, much to the surprise of his colleagues.

Pagliano visited Clinton’s home three times

Footnotes in the FBI report state that Pagliano visited Clinton’s home on three occasions to work on her email system. He visited once in March 2009 to set up the system. That was two months before he took an official job at the State Department.

He visited again in June 2011 to upgrade equipment and again in Jan. 2012 to fix a hardware issue.

“Communicate in code”

During her interview, Clinton discussed a Dec. 27, 2011 email which the intelligence community has determined contained information classified as “SECRET//NOFORN.” Those markings mean that in addition to being highly classified, the information cannot be seen by foreigners.

Clinton defended sending the email, saying that the State Department did not have a clear policy concerning communicating through email during the holidays. (RELATED: FBI Releases Hillary Clinton Investigation Documents)

“It was often necessary to communicate in code or do the best you could to convey the information considering the email system you were using,” she told the FBI.

Clinton’s top 3 aides said they didn’t know about server

Clinton’s State Department chief of staff Cheryl Mills, her top policy adviser Jake Sullivan and Abedin all told the FBI that they did not know about Clinton’s server until after they left the State Department with their boss in Feb. 2013. All three emailed extensively with Clinton.

Laptop with Clinton’s emails was lost in the mail

In Spring 2013, Clinton aide Monica Hanley began a process of transferring emails from Clinton’s server to a laptop and thumb drive.

In Feb. 2014, Hanley sent the laptop to an unnamed individual in order to have the emails transferred to a server managed by Platte River Networks, a Denver-based company Clinton hired to manage her system after she left the State Department.

After Hanley instructed Platte River Networks to wipe the laptop of all its contents, the unnamed person shipped the laptop and a thumb drive through either the U.S. Postal Service or UPS. But the devices never arrived at their destination. They were lost in the mail and have not been recovered. (RELATED: FBI: We Can’t Locate More Than A Dozen Hillary Devices)

“She advised that Clinton’s staff was moving offices at the time; and it would have been easy for the package to get lost during the transition period,” the FBI report states. “Neither Hanley nor [redacted] could identify the current whereabouts of the Archive Laptop or thumb drive containing the archive, and the FBI does not have either item in its possession.”

FBI recovered 17,448 “new” emails

The emails, recovered through forensic investigation, included work-related and personal records. FBI director James Comey said in July that investigators had recovered “several thousand” work-related Clinton emails that she did not give the State Department in Dec. 2014.

FBI couldn’t determine if server was hacked because of missing hardware

[dcquiz] The report states that there is no direct evidence that Clinton’s server was successfully hacked. But the analysis is incomplete because investigators did not have possession of all of the devices that had been hooked up to Clinton’s system or a complete log of server data.

“As a result, FBI cyber analysts relied, in large part, on witness statements, email correspondence, and related forensic content found on other devices to understand the setup, maintenance, administration, and security of the server systems.”

The report notes that Clinton’s system was “potentially vulnerable to compromise” as soon as she started using it.

This article has been edited for clarity.

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