Rumors that Facebook “censored” (or downranked) conservative news content weren’t entirely new in May 2016, but they gained traction when the tech site Gizmodo advanced them in a 9 May 2016 in article reporting that Facebook news curators actively and purposely suppressed right-wing news content solely for ideological reasons:

Facebook workers routinely suppressed news stories of interest to conservative readers from the social network’s influential “trending” news section, according to a former journalist who worked on the project. This individual says that workers prevented stories about the right-wing CPAC gathering, Mitt Romney, Rand Paul, and other conservative topics from appearing in the highly-influential section, even though they were organically trending among the site’s users. Several former Facebook “news curators,” as they were known internally, also told Gizmodo that they were instructed to artificially “inject” selected stories into the trending news module, even if they weren’t popular enough to warrant inclusion—or in some cases weren’t trending at all. The former curators, all of whom worked as contractors, also said they were directed not to include news about Facebook itself in the trending module.

According to Gizmodo, “several former Facebook ‘news curators'” manipulated the flow of conservative information on the social network (for largely unexplained reasons). A highlighted pull quote on the side of the article cited one purported curator as opining that the practice had “a chilling effect on conservative news”:

“Depending on who was on shift, things would be blacklisted or trending,” said the former curator. This individual asked to remain anonymous, citing fear of retribution from the company. The former curator is politically conservative, one of a very small handful of curators with such views on the trending team. “I’d come on shift and I’d discover that CPAC or Mitt Romney or Glenn Beck or popular conservative topics wouldn’t be trending because either the curator didn’t recognize the news topic or it was like they had a bias against Ted Cruz.” The former curator was so troubled by the omissions that they kept a running log of them at the time; this individual provided the notes to Gizmodo. Among the deep-sixed or suppressed topics on the list: former IRS official Lois Lerner, who was accused by Republicans of inappropriately scrutinizing conservative groups; Wisconsin Gov. Scott Walker; popular conservative news aggregator the Drudge Report; Chris Kyle, the former Navy SEAL who was murdered in 2013; and former Fox News contributor Steven Crowder. “I believe it had a chilling effect on conservative news,” the former curator said.

The piece was heavy on speculative reasoning but somewhat light on detail. The curators quoted appeared to be describing a system that favored credible news sources over less reliable ones or trendiness, irrespective of topic:

“We were told that if we saw something, a news story that was on the front page of these ten sites, like CNN, the New York Times, and BBC, then we could inject the topic,” said one former curator. “If it looked like it had enough news sites covering the story, we could inject it — even if it wasn’t naturally trending.”

In another portion of the piece, former curators noted that the sources through which topics were reported (rather than the topics themselves) were factored into the “Facebook trending” curation process:

“Every once in awhile a Red State or conservative news source would have a story. But we would have to go and find the same story from a more neutral outlet that wasn’t as biased.” Stories covered by conservative outlets (like Breitbart, Washington Examiner, and Newsmax) that were trending enough to be picked up by Facebook’s algorithm were excluded unless mainstream sites like the New York Times, the BBC, and CNN covered the same stories. Other former curators interviewed by Gizmodo denied consciously suppressing conservative news, and we were unable to determine if left-wing news topics or sources were similarly suppressed. The conservative curator described the omissions as a function of his colleagues’ judgements; there is no evidence that Facebook management mandated or was even aware of any political bias at work.

Gizmodo‘s report followed up their previous item about Facebook news curation, an article in which the process was described as favorable to credible news outlets but not to sites known for spreading misinformation or inaccurate and poorly vetted claims:

The news curation team writes headlines for each of the topics, along with a three-sentence summary of the news story it’s pegged to, and choose an image or Facebook video to attach to the topic. The news curator also chooses the “most substantive post” to summarize the topic, usually from a news website. The former contractors Gizmodo interviewed said they were asked to write neutral headlines, and encouraged to promote a video only if it had been uploaded to Facebook. They were also told to select articles from a list of preferred media outlets that included sites like the New York Times, Time, Variety, and other traditional outlets. They would regularly avoid sites like World Star Hip Hop, The Blaze, and Breitbart, but were never explicitly told to suppress those outlets. They were also discouraged from mentioning Twitter by name in headlines and summaries, and instead asked to refer to social media in a broader context.

In short, Gizmodo published two articles by the same author about Facebook’s news curation practices. The first piece was more process-oriented and described a predictable policy geared towards locating the most credible items from trusted news sources for any trending topic. The second piece went further in claiming that Facebook was deliberately suppressing conservative news, citing unnamed partisan contract workers as the source for those assertions.

Facebook responded to our query quickly, and told us that they have “rigorous guidelines” in place to ensure consistency and neutrality:

These guidelines do not permit the suppression of political perspectives. Nor do they permit the prioritization of one viewpoint over another or one news outlet over another. These guidelines do not prohibit any news outlet from appearing in Trending Topics.

Interest in the claim persisted, and on 11 and 12 May 2016 purported guidelines for curation were leaked to The Guardian. In response to the controversy, Facebook’s VP of Global Operations Justin Osofsky released a Q&A about Facebook news curation policies on 12 May 2016. Later that day, founder Mark Zuckerberg released the following statement:

I want to share some thoughts on the discussion about Trending Topics. Facebook stands for giving everyone a voice. We believe the world is better when people from different backgrounds and with different ideas all have the power to share their thoughts and experiences. That’s what makes social media unique. We are one global community where anyone can share anything — from a loving photo of a mother and her baby to intellectual analysis of political events. To serve our diverse community, we are committed to building a platform for all ideas. Trending Topics is designed to surface the most newsworthy and popular conversations on Facebook. We have rigorous guidelines that do not permit the prioritization of one viewpoint over another or the suppression of political perspectives. This week, there was a report suggesting that Facebook contractors working on Trending Topics suppressed stories with conservative viewpoints. We take this report very seriously and are conducting a full investigation to ensure our teams upheld the integrity of this product. We have found no evidence that this report is true. If we find anything against our principles, you have my commitment that we will take additional steps to address it. In the coming weeks, I’ll also be inviting leading conservatives and people from across the political spectrum to talk with me about this and share their points of view. I want to have a direct conversation about what Facebook stands for and how we can be sure our platform stays as open as possible. The reason I care so much about this is that it gets to the core of everything Facebook is and everything I want it to be. Every tool we build is designed to give more people a voice and bring our global community together. For as long as I’m leading this company this will always be our mission

If the Facebook Trending curation guidelines released to The Guardian were accurate and legitimate, the documents in no way supported claims Facebook was suppressing “conservative news.” The guidelines as issued simply delineated “best practices” in ensuring that information pushed out via Facebook’s powerful platform remained accurate and credible, filtering out sources that might favor rumor or misinformation over credible reporting. While much attention was paid Facebook’s rota of trusted news sources (including the New York Times, the BBC, The Guardian, and Fox News), that simply appeared to be a failsafe against false or misleading information filtered in by the algorithm but better explained by an outlet with a track record of credibility. The only major mention of blacklisting notably pertained to items with no basis in reality or fact:

A misconception widely repeated in the course of the May 2016 controversy held Facebook was not transparent with respect to the workings of their content curation guidelines. That was demonstrably false, however, as a 21 August 2015 recode article specifically explained such population was accomplished manually once a topic started trending:

Once a topic is identified as trending, it’s approved by an actual human being, who also writes a short description for the story. These people don’t get to pick what Facebook adds to the trending section. That’s done automatically by the algorithm. They just get to pick the headline.

The claims framed as new by Gizmodo in May 2016 were in fact not at all novel or clandestine; recode described the later-controversial practice several months prior with no ensuing ruckus. Facebook Trending’s blacklisting of “junk topics” was not only not a scandalous development, but to be expected following the social network’s crackdown on fake news sites. Prior to Facebook’s rejiggering of its algorithms to account for shoddy and fabricated claims, the social network was a breeding ground for the spread of misleading and falsified claims advanced by unethical hoax purveyors.