Oct. 30 (UPI) -- About 126 million American Facebook users viewed Russian advertisements and posts on their news feeds during the 2016 campaign, Facebook representatives are expected to tell the Senate Committee on the Judiciary in testimony this week, beginning Tuesday.
Some 80,000 posts created by 120 fake Russia-linked pages were directly viewed by about 29 million Americans. Those accounts are allegedly backed by the Internet Research Agency, a pro-Kremlin group.
After shares, likes, comments and follows on Facebook, the number of people who saw the posts more than quadrupled, according to prepared remarks by Facebook general counsel Colin Stretch.
Stretch is scheduled to testify before the Senate Committee on the Judiciary at 2:30 p.m. on Tuesday. Also expected to testify are Sean Edgett, acting general counsel for Twitter and Richard Salgado, director of law enforcement and information security for Google.
The tech companies are under scrutiny by various congressional committees as vehicles for Russia's alleged interference in the 2016 presidential election. U.S. intelligence agencies -- as well as the Senate intelligence committee -- have said they have conclusive evidence Russia interfered in the election.
Facebook, Twitter and Google said they have discovered scores of ads and phony accounts linked to Russia, some of which explicitly mentioned the election. Others broached divisive topics like racism, gun control and immigration.
Congressional investigators are attempting to discover to what extent the ads and posts could have swayed voters' opinions.
Two other congressional hearings related to social media's role in Russian interference are scheduled for Wednesday -- at 9:30 a.m. before the Senate Select Committee on Intelligence and at 2 p.m. before the House Intelligence Committee.
Katherine Haenschen, assistant professor in Virginia Tech's Department of Communication, told UPI earlier this month she's hopeful the hearings will uncover when these companies first learned about the possibility of Russian interference and what steps employees took in response.
"I am highly skeptical that these tech platforms were not aware that something was amiss ... in the case of Facebook with these Russian operatives running these pages," she said. "I'm likewise skeptical that Twitter didn't realize they have a massive Russian bot problem."
On Friday, Facebook announced it is going to start requiring buyers of political advertisements to verify their identities and disclose who paid for the ads.
Under current U.S. law, digital platforms like Facebook, Google and Twitter aren't required to disclose who buys political ads the way more traditional media are required to like television and radio.