Mere days after Tom Stocky, Facebook’s Trending News manager, rejected reports that his subordinates “artificially inject” items into its list of trending news stories, a leak of internal guidelines published in The Guardian show that the company does exactly that.

The document shows that Facebook’s team behaves like a typical Old Media outlet, with editors selecting and approving stories at virtually every stage of the process. The company also keeps a list of 1,000 “trusted” outlets that it uses in its Trending News feature.

The document also instructs staffers to check if a story is headlining on mainstream outlets like CNN, BBC, Fox News, and The New York Times before assigning it “national-level” importance. This is in stark contrast to the company’s outward claim that its Trending News feature merely reflects what’s currently trending among its userbase.

Moreover, editors are given the power to insert new topics into the trending list, provided they pass a particular threshold of popularity. This specifically contradicts a claim by Tom Stocky, the company’s manager of Trending News, who earlier this week said “we do not insert stories artificially into trending topics, and do not instruct our reviewers to do so.”

This follows a week of damaging reports from anonymous sources at the company, who told Gizmodo that members of Facebook’s Trending News feature, which is intended to reflect only the most popular news topics being discussed on Facebook, routinely discriminated against conservative news sources.

This news is likely to add to the political momentum building against Facebook, which now faces the prospect of a congressional inquiry into political bias at the company. Earlier this week, Republican Senator Jim Thune sent CEO Mark Zuckerberg a letter demanding answers on the issue. The RNC has also put out a statement calling on Facebook to address its bias against conservatives.

According to The Guardian, the lesson of the latest leak is clear. Facebook, once the centre of a supposedly people-powered social media revolution, is now starting to behave like a traditional mainstream media outlet. Its news operation is “now akin to a traditional media organization,” says The Guardian.

In a statement to the newspaper, Facebook vice-president Justin Osofsky maintained that it did not discriminate politically.

The guidelines demonstrate that we have a series of checks and balances in place to help surface the most important popular stories, regardless of where they fall on the ideological spectrum. Facebook does not allow or advise our reviewers to systematically discriminate against sources of any political origin, period. What these guidelines show is that we’ve approached this responsibly and with the goal of creating a high-quality product – in the hopes of delivering a meaningful experience for the people who use our service.

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