U.S. intelligence agencies have concluded that Russian military intelligence officials used American social media platforms to manipulate voter opinion. | Sean Gallup/Getty Images Facebook faces backlash over Russian meddling The social media giant is under new scrutiny from Congress, watchdogs and Rachel Maddow after an about-face.

Facebook is facing intense political fallout and thorny legal questions a day after confirming that Russian funds paid for advertising on the social media platform aimed at influencing voters during last year’s presidential election.

Mark Warner, the vice chairman of the Senate Intelligence Committee, said Thursday he hopes to call executives from Facebook, Twitter and other social media companies to testify publicly about what role their companies may have played, however unwittingly, in the wider Kremlin effort to manipulate the 2016 White House race.


"I think we may just be seeing the tip of the iceberg,” the Virginia Democrat told reporters in response to Facebook’s Wednesday disclosure that apparent Russian-tied accounts spent some $150,000 on more than 5,200 political ads last year. Warner said Facebook’s disclosure was based only on a “fairly narrow search” for suspicious ad-buying accounts.

Facebook was also the target of a 20-minute monologue by the MSNBC host Rachel Maddow on Wednesday night, in which she pointedly noted the company’s past denials to media outlets including Time , McClatchy and CNN that it had found any Russian-bought ads.

“It raises very interesting questions about Facebook accepting that money to influence the U.S. election without noticing that it was from a foreign source,” she said, adding the Russian purchasers and Americans who knew about the ad buys were now exposed to criminal proceedings.

U.S. intelligence agencies have concluded that Russian military intelligence officials used American social media platforms to manipulate voter opinion. Federal investigators are working to learn more about that effort, including whether anyone within the U.S. might have assisted the Russian effort with political advice.

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Regardless of whether any Americans might have colluded with the effort, it is illegal for foreign nationals to spend money meant to influence an American election. On Thursday, the government watchdog group Common Cause filed petitions with special counsel Robert Mueller and Deputy Attorney General Rod Rosenstein, as well as the Federal Election Commission, seeking an investigation into that question.

“The violations of federal campaign finance law alleged in the attached complaint pose a direct threat to democracy and national security in the United States,” Paul Ryan, vice president of policy and litigation at Common Cause, wrote in his letter to Mueller and Rosenstein.

Facebook’s Wednesday disclosure was an about-face after months of public denials that Russian money was behind political ads on its platform.

The company changed its tune Wednesday with a blog post from its chief security officer, Alex Stamos, detailing an internal review that found a small amount of ads with Russian funding specifically mentioned Donald Trump and Hillary Clinton—although most amplified divisive social and political issues like LGBT rights, race, immigration and gun rights.

A quarter of the Russian-linked ads, Stamos added, were geographically targeted at specific Facebook audiences in the U.S., and most of them ran in 2015 before the first primaries and caucuses when the GOP and Democratic presidential fields were still packed with multiple candidates.

A Facebook official separately confirmed that the accounts it had uncovered had “links” to a Russian company, the Internet Research Agency, known to create fake Twitter and Facebook accounts which spread pro-Kremlin propaganda.

In its January assessment of Russia’s election meddling, U.S. intelligence agencies determined the “likely financier” of the Internet Research Agency’s army of “professional trolls located in Saint

Petersburg is a close [Russian President Vladimir] Putin ally with ties to Russian intelligence.” The report also concluded Russian trolls undermined Clinton by spreading politically damaging information found in emails hacked and stolen from her campaign chairman, John Podesta, and the Democratic National Committee. The emails were released by WikiLeaks, whose founder, Julian Assange, has denied they were provided by Russia.

Facebook’s disclosures have so far sparked the loudest outcry from Democrats, though Eric Wilson, the digital director from Republican Marco Rubio’s 2016 presidential campaign, jumped in via Twitter to note “Facebook is keeping every penny” from the Russian-affiliated ads.

Speaking to reporters in the Capitol, Warner said he was “pleased” Facebook had presented Senate staff with its internal findings but noted that “one of the disappointments” was the company’s decision not to release any of the Russian-linked ads it did find.

Warner added that both Facebook and Congress were in “unchartered territory” as it examined foreign interference in U.S. elections via social media. But he said it was important that Congress shed light on what happened, including through public hearings with technology executives.

“The American people deserve to know both the content and the source of information that is being used to try to affect their votes,” he said.

A Facebook spokesman said the company would “continue to investigate and will cooperate with authorities” on the extent of Russian influence on its platform while declining comment on the calls for Mueller and the FEC to dig deeper into who paid for the ads.

Officials at DOJ and in Mueller’s office also declined comment.

At the FEC, Commissioner Ellen Weintraub declined comment on the Common Cause petition. But she did express concern about the prospect of Russian financing to influence a U.S. election.

“I do think this raises important issues, important questions about our internet disclosure rules and whether the American people are in a position to know where the information they learn on the internet is coming from,” she told POLITICO.

On her Wednesday night program, Maddow told her viewers that Facebook’s admission opened the door to a serious round of criminal inquiries.

“This is direct evidence confirmed by Facebook of a discreet clear crime committed in the course of the Russian attack on our election,” she said. “Now, good luck bringing in the Russian military intelligence service into court to face the music for that particular crime, I know. But it’s a crime.”