As a result of the review by Sen. Jon Kyl, R-Ariz., and a team at law firm Covington & Burling, Facebook said it would commit to taking steps to be more transparent about how it ranks News Feed content and enforces community standards.
The report said the company has adjusted its "sensational" advertising policy to pull back restrictions on anti-abortion ads showing medical tubes connected to human bodies.
"Facebook has recognized the importance of our assessment and has taken some steps to address the concerns we uncovered. But there is still significant work to be done to satisfy the concerns we heard from conservatives," the report said.
Kyl and the team interviewed more than 130 conservative groups, individuals and lawmakers who "use, study, or have the potential to regulate Facebook," according to the report. The review revealed several categories in which conservatives have expressed concerns about bias, including Facebook's advertising policies and enforcement and its content distribution and algorithms.
Conservatives interviewed told the team they feared algorithms that prioritize user content do so "in ways that suppress their viewpoints." Several pointed to Facebook's algorithm change in 2018 that favored content from users' friends and families, arguing it also disproportionately limited the reach of conservative news content. Interviewees from mid-size grassroots organizations told the team that Facebook's appeals process for content moderation decisions were too opaque.
Interviewees also raised concerns about Facebook having a hate speech policy, saying the notion is highly subjective. Many also said Facebook relies too heavily on "left-leaning organizations to identify hate groups."
Many conservatives interviewed ultimately said the problems they see on Facebook likely stem from employees biased against their viewpoints.
While Kyl's team began interviewing conservatives in May 2018, the results come as allegations of conservative bias against the company have continued to bubble up. Executives from Facebook and other tech platforms including Google and Twitter have had to face lawmakers in recent months to defend their content moderation and distribution practices. Sen. Josh Hawley, R-Mo., has even introduced legislation tying legal protections for tech companies to voluntary audits that would assess whether their platforms' algorithms and content removal practices are "politically neutral."