WASHINGTON, May 10 (UPI) -- The chairman of a U.S. Senate committee wants Facebook to respond to reports that employees suppressed news articles from politically conservative websites on the mammoth social media platform.
"Facebook must answer these serious allegations and hold those responsible to account if there has been political bias in the dissemination of trending news," John Thune, R-S.D., said Tuesday after sending a letter to Facebook Chairman and CEO Mark Zuckerberg. "Any attempt by a neutral and inclusive social media platform to censor or manipulate political discussion is an abuse of trust and inconsistent with the values of an open Internet."
Thune, chairman of the Senate Committee on Commerce, Science and Transportation, was responding to a report by tech news outlet Gizmodo, in which an unnamed Facebook news curator said conservative sites' stories were left off Facebook's "trending news" sidebar.
Facebook denied the report, saying it has "rigorous guidelines" to ensure political neutrality in displaying news to its 1.6 billion users worldwide.
"We take allegations of bias very seriously. Facebook is a platform for people and perspectives from across the political spectrum. Trending Topics shows you the popular topics and hashtags that are being talked about on Facebook," the company said in an emailed statement.
"These guidelines do not permit the suppression of political perspectives. Nor do they permit the prioritization of one viewpoint over another or one news outlet over another. These guidelines do not prohibit any news outlet from appearing in Trending Topics."
Thune's letter asks Zuckerberg to provide answers to his questions no later than May 24.
Thune, whose committee has legislative oversight on Internet communications, wants details on the organizational setup of the feature and how the stories are chosen. In addition, he want to know what steps were being taken to investigate the allegations.
Th person quoted in the Gizmodo article said workers prevented stories about the Conservative Political Action Conference, Mitt Romney, Rand Paul and other conservative topics from appearing in the section.
Several former Facebook news curators also told Gizmodo they were instructed to artificially "inject" selected stories into the trending news module.
Facebook Vice President Tom Stocky says popular topics first surface by an algorithm and are then audited by team members to confirm that the topics are in fact trending news in the real world.
The former curators, all contractors, also told Gizmiodo they were directed not to include news about Facebook itself in the trending module.
Several hours after Gizmodo's report, editors there said they started seeing it as a topic in Facebook's trending section.
Also, Facebook says it is a sponsor of the Republican and Democratic national conventions.