That means roughly one-third of the US population was exposed to content from Russia-backed operatives over a two-year period, according to leaked testimony for a Tuesday hearing.
Facebook, Twitter and Google plan to tell congressional investigators this week that Russia's efforts to use the social networks to sow discontent during the 2016 US election were much broader than originally thought.
About 126 million Americans, or roughly one-third of the nation's population, were exposed to Russian-backed content on Facebook during the 2016 presidential election, according to a prepared statement the social network reportedly plans to present to the Senate Judiciary Committee on Tuesday.
Facebook said Russia-backed operatives published about 80,000 posts that were delivered to approximately 29 million people on the social network during a two-year period, CBS News reported Monday, citing a source familiar with Facebook's planned testimony. The posts may have spread to three times that many people after they were shared, liked and followed by Facebook users.
Those figures are much higher than the 10 Facebook million users it said in early October had seen Russian-linked ads. The social-networking giant said in September it had identified about 500 "inauthentic accounts" that bought $100,000 worth of ads that targeted highly politicized social issues such as immigration, guns and LGBT rights.
Facebook's disclosure marked a new turn in the high-profile Russia investigation. The committee has raised issues concerning President Donald Trump's election last year, the involvement of his children and the actions of his staff. At issue is how much the Russian government may have attempted to influence the electorate and whether Trump or anyone working for him was knowingly involved. Trump has repeatedly denied involvement.
Google also shared more about its own investigation into election meddling on Monday, saying it found the Internet Research Agency, a Russian-government affiliated troll farm, spent $4,700 on search-and-display ads on its platforms during the 2016 election cycle. It also said it found 18 YouTube channels associated with the Russia-backed influence effort.
Twitter, meanwhile, found more than 2,700 accounts it believes were associated with the IRA campaign, according to a source familiar with the testimony. That number is substantially higher than the 201 accounts it said in September it believed were linked to the meddling effort. Those 2,700 accounts have been suspended as Twitter says it has pledged to Congress it will inform them if they uncover more accounts.
Twitter's testimony will include that tweets from Russian-linked, automated accounts made up 0.74 percent of all of the election-related tweets on Twitter from Sept. 1 to Nov. 15, 2016. Those tweets received 0.33 percent of all the impressions on election-related tweets.
The figures were provided as part of written testimony the companies plan to deliver to the Judiciary Committee, as well as the Senate and House Intelligence Committees on Wednesday. They're all investigating Russia-backed efforts to influence the 2016 US election.
The Russian government has denied making any attempts to influence the election.
First published Oct. 30 at 3:45 p.m. PT.
Updated at 5:06 p.m. PT: Adds information from Google and Twitter.
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