Allen repeatedly asked Sandberg when the social network found out about the ads - and Sandberg eventually said the company had heard about the ads around the time of the United States election. USA intelligence agencies have concluded that Russian Federation used cyber-enabled means in an attempt to help Trump win the White House, an allegation the Kremlin has denied.
Sandberg is meeting with elected officials in Washington this week ahead of a House hearing at which executives from Facebook, Twitter and Google are expected to testify.
She defined fake news as "things that are false hoaxes" and said Facebook is working to stamp out the bad information by teaming up with third-party fact checkers and warning users before they share news deemed fake by Facebook.
The meeting came ahead of a November 1 House Intelligence Committee hearing at which Facebook, Twitter and Google are expected to testify.
Sandberg made the trip to Washington D.C.to inform U.S. lawmakers about progress in Facebook's internal investigation into the Russian adverts on the site.
Facebook went on to state that "our analysis suggests these accounts and Pages were affiliated with one another and likely operated out of Russian Federation".
Google admitted on Monday it had found evidence that Russian operatives attempted to meddle in last year's USA presidential election by spending tens of thousands of dollars on politically divisive advertisements across its platforms.
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The Pentagon also declined to comment specifically on reports of the potential breach, but spokesman Col. A ministry spokesman declined to confirm the report, citing intelligence matters.
Sandberg did say that Facebook and Congress would release data on the Russian ad targeting when they release the ads to the public next month.
In addition, Robert Mueller, a former director of the Federal Bureau of Investigation, is conducting a criminal probe, including whether President Trump's campaign colluded with Russian operatives during the election season. Russian Federation apparently took advantage of controversies surrounding Hillary Clinton [the email scandal that rocked her campaign], and further dug in with the said ads bought from some Silicon Valley giants.
"What we really owe the American people is determination" to do "everything we can" to defend against threats and foreign interference, Sandberg said.
"We don't want this kind of foreign interference" on Facebook, Sandberg added.
Facebook said last month that the ads focused on divisive political messages, including LGBT issues, immigration and gun rights, and were seen by an estimated 10 million people.
Moreover, Sandberg said she disagreed with Twitter's initial decision to take down Congressional candidate Marsha Blackburn's campaign ad because it included "an inflammatory statement that is likely to evoke a strong negative reaction". "But the question is, 'Should divisive political or issue ads run?' Our answer is yes because when you cut off speech for one person you cut off speech for all people", she said.