In late August, the social network put an algorithm in charge of its "trending" feature, selecting the most popular topics, articles and keywords. The change came after allegations in the spring that the contract workers who curated the news headline feature altered which articles appeared for political reasons.

Yet in recent days, as The Wall Street Journal reports, the "trending" lists have appeared more flawed than when humans were in charge. There have been false stories, misidentified keywords, and celebrity gossip in the place of more serious news.

"This doesn't seem like an appropriate solution," said Jason Turcotte, assistant professor of communication at California State Polytechnic University, Pomona. "Algorithms don't necessarily respond to news values or journalistic ethics. Algorithms respond to keywords, search terms and trends."

 In doing away with the team of curators who had run "trending," Facebook redefined what it perceives as news. It modified the guidelines for the feature, giving more importance to smaller publications. "It's intentionally broad so we can be inclusive of a wide range of interests," Facebook said in the guidelines for the staff, published in late August.