Facebook has confirmed a Washington Post report indicating that its ad sales team had sold advertising to a "shadowy Russian company" ahead of the 2016 Presidential election. These sponsored FB posts, in turn, were used to "target" American voters, either by directly naming presidential candidates or by focusing on "politically divisive issues."

This information was disclosed to congressional investigators, according to "several people familiar with the company’s findings," after an internal Facebook investigation this spring linked $100,000 of ad buys to a Russian company known as the Internet Research Agency. The WP's sources described the company as a pro-Kremlin "troll farm." Facebook's investigation confirmed, via "digital footprints," that 3,300 ads from 470 "suspicious and likely fraudulent Facebook accounts and pages" were all linked to the same Russian company.

Those ads were targeted, according to an unnamed Facebook official, at users who'd "expressed interest" in politically charged topics such as African-American social issues, the Second Amendment, immigration, and the LGBT community. Facebook declined to show congressional investigators the exact content of these ads, citing both the company's data policy and federal law about disclosing user data and content.

Facebook's official post on the matter confirmed nearly every detail in the WP's report, while clarifying that this ad analysis covered a span of nearly two years, from June 2015 to May 2017. It estimated that 25 percent of the ads in question were geographically targeted and that "more ran in 2015 than 2016." Facebook pointed out these ads' intent to "amplify divisive messages," and this intent was also demonstrated in techniques spelled out by the company's April 2017 white paper.

The official post mentioned an additional, broader net cast to identify other Russia-connected ads sold during that span—"with very weak signals of a connection and not associated with any known organized effort," it clarified. This additional pool of ads totaled $50,000 spent on roughly 2,200 ads.

"We have shared our findings with US authorities investigating these issues, and we will continue to work with them as necessary," the Facebook post said.

Neither the WP report nor Facebook's official confirmation answered exactly how many users were reached by these ads. Ars Technica loaded a Facebook ad-purchase order to buy $100,000 of advertising that targeted anyone interested in "the Second Amendment" or "illegal immigration," and it quoted a "potential reach" of 1.4 million Facebook users. This was before narrowing the ad buy any further with other topics or location-specific filters. It could very well differ from the reach of a similar ad buy in 2016.

Any ad purchases as described by this WP report would violate FEC rules prohibiting foreign nationals and governments from either spending money or making contributions that influence US elections on the federal, state, or local level.

As the WP points out, this revelation follows a Time report from May claiming that US intelligence officials had found proof of politically targeted, Kremlin-affiliated Facebook ad buys during the 2016 Presidential election. At the time, a Facebook representative said that the company had seen "no evidence" of such ad-buying activity.