(CBS News) In the wake of the sex scandal that led to David Petraeus' resignation from his position as the director of the Central Intelligence Agency, the topic of email privacy has surfaced in the minds of many.
Petraeus submitted his resignation to President Obama last week, citing an extramarital affair. Law enforcement raised concern over emails the former CIA director exchanged with journalist Paula Broadwell, who authored his biography "All In: The Education of General David Petraeus."
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Emails carry unique identifying information called metadata. According to the Wall Street Journal, agents used metadata footprints to trace the origin of the emails back to Broadwell.
So how did supposed private emails lead to the downfall of the former CIA director? First thing to note is that emails are never 100 percent private. That's not to say that anyone can access your electronic messages, but the possibility is always looming. It is important to understand where privacy ends and public domain begins.
"The system is remarkably similar to the postal system. You can seal the envelope and hide what's inside, but it contains a postmark of where it came from and where it's going," ZDNET's Zack Whittaker explains. "It may even have your fingerprints on it. All of this information outside the contents is 'metadata.'"
Who owns what?
"The government can't just wander through your emails just because they'd like to know what you're thinking or doing," Stewart Baker, a former assistant secretary at the Homeland Security Department who's now in private law practice, told the Associated Press. "But if the government is investigating a crime, it has a lot of authority to review people's emails."
Petraeus and Broadwell used Google-owned Gmail to communicate. According to Google's terms of service, the company may share personal information about an account holder under if Google believes that the data is "reasonably necessary" to:
- Meet any applicable law, regulation, legal process or enforceable governmental request.
- Enforce applicable Terms of Service, including investigation of potential violations.
- Detect, prevent, or otherwise address fraud, security or technical issues.
- Protect against harm to the rights, property or safety of Google, our users or the public as required or permitted by law.
According to Google's transparency report, government surveillance is on the rise. The report says that government agencies from around the world made a total of 20,938 inquiries in the first half of 2012. When Google launched its transparency report in 2010 the number of requests between July to Dec. 2009 was 12,539.
Google released this statement to CBS News:
"Protecting the privacy and security of our users is incredibly important to us. Like all law-abiding companies, we respect valid legal process. Whenever we receive a request, we make sure it meets both the letter and spirit of the law before complying. When possible and legal to do so, we notify affected users about requests for user data that may affect them. And if we believe a request is overly broad, we will seek to narrow it."
Under the 1986 Electronic Communications Privacy Act, federal authorities need only a subpoena approved by a federal prosecutor -- not a judge -- to obtain electronic messages that are six months old or older. To get more recent communications, a warrant from a judge is required. This is a higher standard that requires proof of probable cause that a crime is being committed.
Public interest groups are pressing Congress for the law to be updated because it was written a quarter-century ago, when most emails were deleted after a few months because the cost of storing them indefinitely was prohibitive. Now, "cloud computing" services provide huge amounts of inexpensive storage capacity. Other technological advances, such as mobile phones, have dramatically increased the amount of communications that are kept in electronic warehouses and can be reviewed by law enforcement authorities carrying a subpoena.
What about email drafts?
Petreaus and Broadwell carried out much of their communication using email drafts, instead of sending messages. What they may have failed to realize was that their saved emails were still being stored in Google's servers.
Even if the messages were not sent from one account to another, Google still knows where a Gmail account is logged in from. Additionally, drafts may be more vulnerable to prying eyes. The American Civil Liberties Union point out that sent emails -- as well as drafts -- are not classified as electronic storage, excluding them from warrant protection under the Stored Communications Act.
The bottom line
Your emails my be private from those who are only curious about the content of your messages, but anyone with a warrant or subpoena may be able to gain access to your account, and this might not even be necessary if your email provider agrees.
"You know if the director of the Central Intelligence Agency cannot protect his privacy online, what hope is there for the rest of us?" Chris Soghoian, principal technologist at the ACLU told Marketplace.
"What that means is, if you were trying to hide you tracks, whether from a jealous spouse or even an online advertising company. You have to get everything just right. If you make one small mistake that veil of anonymity that you have put all that work into creating can be pierced and your identity can be revealed."
It started in May with a spiteful email to the top U.S. commander in Afghanistan. An anonymous writer warned Gen. John Allen that a friend with whom he was meeting in Washington the following week was trouble and he should stay away from her.
Allen thought the email was a joke because he didn't know how anybody else would know about his personal plans with his friend, Florida socialite Jill Kelley, a person close to Kelley said.
That email started a chain of events that led to the downfall of CIA Director David Petreaus, put Allen's career on hold and landed a decorated FBI agent in hot water for talking about an ongoing investigation. The FBI traced that email and others of a similar vein to Paula Broadwell, Petraeus' biographer, who agents would soon learn had also been his lover.
The fast-moving scandal broke just days after President Barack Obama was elected to a second term in office. Obama's administration had been on the defensive for weeks because of a terror attack on the U.S. Consulate in Benghazi, Libya, that left four Americans dead. Briefings on the attack had been postponed until after the election and are now focused more immediately on Petraeus' love life than on how terrorists were able to attack the poorly defended consulate.
Obama said Wednesday he's seen no evidence that national security was damaged by the revelations that ended his CIA director's career and imperil that of his Afghanistan war commander. But lawmakers aren't taking Obama's word for it and grilled FBI and CIA officials privately about the same issues: whether national security was jeopardized by the case and why they didn't know about the investigation sooner.
The FBI's investigation of the matter began last summer when Kelley turned over anonymous emails that had been sent to her and Allen. The first anonymous email was sent to Allen in May, under the pseudonym "Kelleypatrol," the person close to Kelley said, speaking on condition of anonymity because of the ongoing investigation.
In midsummer, Kelley shared these emails with an FBI agent, Frederick W. Humphries, whom she met at an FBI community program in 2011.
Concerned that someone was tracking the movements of Allen and Petraeus, the FBI agent set the investigation in motion when he handed the information to the FBI's cyber squad in Tampa. But Humphries was cut out of the loop and took that to mean the FBI was not taking the case seriously, the person close to Kelley said. Humphries would later reach out to Congress in a whistle-blower role that has now landed him under internal scrutiny at the bureau.
But the FBI was taking the case seriously and continues to investigate.
The FBI has found a substantial number of classified documents on Broadwell's computer and in her home, according to a law enforcement official who spoke on condition of anonymity because the official was not authorized to speak publicly about the case. Broadwell has told agents that she took classified documents out of security government buildings, the official said. Unauthorized possession of classified national defense documents is a crime. The Army has suspended Broadwell's security clearance, which she had as a former Army intelligence officer.
The FBI also found emails between Kelley and Allen that were turned over to the Defense Department for investigation. Obama has put on hold Allen's nomination to become the next commander of U.S. European Command as well as the NATO supreme allied commander in Europe until Pentagon investigators are able to sift through the emails that involve Allen and Kelley.
Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, said Thursday he still expects Allen to eventually take over the European Command, but acknowledged, "I see this investigation and how long it could take affecting that."
In an interview with American Forces Press Service, Dempsey said "I absolutely have confidence" in Allen's ability to continue in command in Afghanistan despite the distraction of the scandal.
Speaking at a news conference in Bangkok on Thursday, Defense Secretary Leon Panetta also said he retains confidence in Allen. He added that he knows of no other senior U.S. military officers being linked to the Petraeus investigation.
The Pentagon chief also told reporters he could not rule out the possibility that the Taliban in Afghanistan would try to use Petraeus' admission of an extramarital affair for propaganda purposes. Petraeus was Allen's predecessor as top U.S. commander in Afghanistan.
FBI Director Robert Mueller and Deputy Director Sean Joyce met privately with legislators on both sides of the Capitol on Wednesday to explain how the investigation unfolded. They met first with Senate Intelligence Committee Chairwoman Dianne Feinstein, D-Calif., and ranking Republican Saxby Chambliss of Georgia, then crossed the Capitol to meet with the House Intelligence Committee.
Acting CIA Director Michael Morell went before the House panel next, after meeting a day earlier with top Senate intelligence officials to explain the CIA's take on events that led to Petraeus' resignation.
The questioning on Capitol Hill was continuing Thursday. And Kelley's decision to contact her friend at the FBI continues to reverberate months later.
Her own pass to enter MacDill Air Force Base in Florida had been indefinitely suspended, a move that ends her easy access to the senior military officials that dot her social world.