Republican U.S. Senator John Thune says Facebook has been "forthcoming" about how it determines what appears in its Trending Topics section, and adds that he appreciates the company's efforts to address allegations of bias against conservative viewpoints.
Thune asked the company to answer questions about its practices after reports cited a former Facebook employee saying contractors on the Trending Topics team routinely suppressed stories that would interest conservative users.
He said if the allegations were true, then Facebook was misleading the public in its claim to be a platform for people and perspectives from across the political spectrum.
The company responded Monday with a 12-page letter from Facebook General Counsel Colin Stretch who said an internal review found no evidence of systemic political bias in either the selection or prominence of stories.
"In fact, our analysis indicated that the rates of approval of conservative and liberal topics are virtually identical in Trending Topics," Stretch said. But he did not exclude the possibility that since the feature launched in 2014 there have been "isolated improper actions or unintentional bias."
The letter addressed some of the specific allegations, including that Facebook suppressed news about Republicans Ted Cruz, Rand Paul, Mitt Romney and Scott Walker. The company said its probe did not substantiate the claims, and that stories about each figure appeared as trending topics dozens of times.
"Two of the most frequently accepted topics since early 2015 are presumptive Republican presidential nominee Donald Trump and #GOPDebate," Stretch said.
Thune, who chairs the Senate's Committee on Commerce, Science and Transportation, said after receiving the letter he looks forward to Facebook's actions meeting its public statements.