In a press release Facebook said it had found “no evidence of systematic political bias in the selection or prominence” of the featured topics. Nevertheless, as isolated cases of bias couldn’t be fully excluded, the company said it’s making “improvements” to Trending Topics. These include clarifying the guidelines and additional training of the reviewers working on the news selection of the project.

What is striking is that Facebook views any potential issue as relating to the human curators exclusively: in a response about the issue to John Thune, the chairman of the US Senate commerce committee, the company said: “We currently use people to bridge the gap between what an algorithm can do today and what we hope it will be able to do in the future.”

Facebook is therefore espousing the idea that algorithms are inherently more neutral than human editorial processes – an increasingly contested view.