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A group of Facebook engineers identified a “massive ranking failure” that exposed as much as half of all News Feed views to “integrity risks” over the past six months, according to an internal report on the incident obtained by The Verge.
The engineers first noticed the issue last October, when a sudden surge of misinformation began flowing through the News Feed, notes the report, which was shared inside the company last week. Instead of suppressing dubious posts reviewed by the company’s network of outside fact-checkers, the News Feed was instead giving the posts distribution, spiking views by as much as 30 percent globally. Unable to find the root cause, the engineers watched the surge subside a few weeks later and then flare up repeatedly until the ranking issue was fixed on March 11th.
In addition to posts flagged by fact-checkers, the internal investigation found that, during the bug period, Facebook’s systems failed to properly demote nudity, violence, and even Russian state media the social network recently pledged to stop recommending in response to the country’s invasion of Ukraine. The issue was internally designated a level-one SEV, or Severe Engineering Vulnerability — a label reserved for the company’s worst technical crises, like Russia’s ongoing block of Facebook and Instagram.
Source: TheVerge
