A Facebook Bug Mistakenly Elevated Misinformation, Russian State Media for Months

A group of Facebook engineers identified a massive ranking failure that exposed as much as half of all News Feed views to potentialintegrity risks over the past six months, according to an internal report. The engineers first noticed the issue last October when a sudden surge of misinformation began flowing through the News Feed. Instead of suppressing posts from repeat misinformation offenders that were 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. The engineers were unable to find the root cause of the surge and had to fix it 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 probable nudity, violence, and even Russian state media the social network recently pledged to stop recommending in response to the country. The issue was designated as a level-one SEV, or site event, which is reserved for high-priority technical crises like Russia's ongoing block of Facebook.