In April 2019, Facebook COO Sheryl Sandberg emailed one of Facebook's cybersecurity teams with a special project. They were to help a Facebook user who had emailed Sandberg to complain about the bullying he was receiving on the social network. People were hacking his account and making fake accounts pretending to be him, then posting in ways that made fun of his disability. In previous years, this type of special assignment would've been out of the ordinary for Sandberg, the Facebook executive charged with growing the company's ad business and handling its communications. But after a couple of hard years where Facebook was slammed for prioritizing growth over protecting user data, and for its aggressive stance toward the press, Sandberg has placed a higher priority on user security, privacy and mental health, according to a former employee who knew about her special request. For Sandberg, the 2010s saw the highest of highs and lowest of lows. She started the decade as a rising female business icon. But as the decade closes, Sandberg is one of the two faces of the company that has come to represent the exploitation of people's privacy and the hubris of the technology industry.

Leaning in and rising up

When she was hired away from Google to be Facebook's COO in 2008, Sandberg was 38 — young for the role, but 15 years older than founder and CEO Mark Zuckerberg. Zuckerberg brought Sandberg in to be his No. 2, but she also served as the de facto adult in the room for the young company. Perhaps most importantly, Sandberg was charged with growing Facebook's revenue and advertising businesses in preparation for an inevitable IPO. She succeeded handsomely. Before her arrival, Facebook had generated a little more than $150 million in revenue in 2007. Sandberg helped grow that figure nearly 2,400% to $3.7 billion by 2011.

Sandberg's handling of the Facebook ad business set up the company nearly perfectly for its 2012 IPO. Upon hitting the public market that May, Facebook raised $16 billion and reached a valuation of $104 billion. The next month, Sandberg was rewarded for her work with a position on the Facebook board of directors. She was the first woman to join the board. As Facebook grew — the company reached its 1 billionth user in October 2012 — so too did Sandberg's national profile. Sandberg seized the moment, and in March 2013, she published "Lean In: Women, Work, and the Will to Lead." She also established a foundation named after the book to focus on women's issues in the workplace. (It was later renamed the Sheryl Sandberg & Dave Goldberg Family Foundation.) The book was a manifesto on women in the workplace, and it was a tremendous success, selling millions of copies and landing Sandberg on magazine covers and TV shows. Although criticism of the book has grown in recent years, especially in regard to its ignorance about minority women in the workplace, "Lean In" catapulted Sandberg into a household name and a role model and icon for women across the globe. But Sandberg's life took a tragic turn in May 2015. Sandberg's husband, Dave Goldberg, suffered a coronary arrhythmia and died while the two were vacationing in Punta Mita, Mexico. In interviews since then, Sandberg has said Goldberg's death was devastating and caused her to feel huge grief and loneliness. She wrote about how she handled the experience and recovered in a second book published in April 2017 titled "Option B: Facing Adversity, Building Resilience, and Finding Joy." Goldberg's death also helped spark Facebook's February 2017 move to extend its employees' bereavement leave to 20 days, a move for which Sandberg was widely praised. Speculation about Sandberg's political future gained momentum in 2016. Sandberg is a staunch supporter of the Democratic Party and served in the Treasury Department during Bill Clinton's administration. She was also a supporter of Hillary Clinton, and in the lead-up to the 2016 U.S. election, there were reports that Sandberg was in consideration for a Cabinet position if Clinton were elected. Sandberg denied those reports, saying "I really am staying at Facebook."

Trump and everything after

Whether or not she had plans to leave Facebook, any political aspirations became moot when Donald Trump was elected in November 2016. Sandberg was among a delegation of tech executives who attended a summit held by Trump in New York in December 2016, where she was photographed grimacing to the right of Vice President-elect Mike Pence.

(L to R) Jeff Bezos, chief executive officer of Amazon; Larry Page, chief executive officer of Alphabet; Sheryl Sandberg, chief operating officer of Facebook; then-Vice President-elect Mike Pence and then-President-elect Donald Trump meet at Trump Tower, December 14, 2016. Getty Images

In April 2017, Facebook published a case study saying it had detected "information operations" from outsiders intended to sway voters in the 2016 election. For instance, Facebook said, some groups had stolen information from sources such as email accounts to harm particular political actors. The study was followed by subsequent reports from Facebook and the U.S. government over the next few months detailing how Russian groups had used Facebook extensively to try and influence voters, including by planning fake rallies around controversial subjects. But the 2016 presidential election would end up causing a much bigger disruption for Sandberg and the company. In March 2018, The Guardian and The New York Times reported that Cambridge Analytica, a political consulting firm, had improperly accessed the data of 50 million Facebook users, and had used that data to target voters on Facebook to get them to support Donald Trump in the 2016 presidential campaign. The number was later revised to 87 million Facebook profiles. The company's clumsy response to the reports didn't help. Facebook first tried to get ahead of the reports by publishing a Friday night blog post on March 16, saying it was suspending Cambridge Analytica for improperly accessing user data. After the reports went live on Saturday, Sandberg and the rest of the company did not address the public for five days. The scandal set the stage for a tumultuous 2018 that enveloped the entirety of Facebook and changed people's perceptions of the company's executives. In September 2018, Sandberg was called to Washington to testify in regard to the role Facebook had played in Russian interference into the 2016 U.S. election. "We know we can't stop interference by ourselves," Sandberg said in her remarks. "We don't have all the investigative tools that the government has, and we can't always attribute attacks or identify motives."

Facebook COO Sheryl Sandberg testifies before the Senate Intelligence Committee on September 5, 2018. Jim Watson | AFP | Getty Images