[The report] articulates the connection between surveillance-based business models and the health of democracy... [The repot argues that] instead of seeking to hold digital platforms liable for content posted by their users, regulators and advocates should instead focus on holding companies accountable for how content is amplified and targeted... Armed with five years of research on corporate policies that affect online speech and privacy, we make a case for a set of policy measures that will protect free expression while holding digital platforms much more accountable for the effects of their business models on democratic discourse.

... Key recommendations for corporate transparency: 

• Companies’ rules governing content shared by users must be clearly explained and consistent with established human rights standards for freedom of expression.
• Companies should enable users to decide whether and how algorithms can shape their online experience... 
• People whose speech is restricted must have an opportunity to appeal... 
• Companies must regularly publish transparency reports.

[refers to Alphabet, Facebook, Google, Microsoft, Twitter, YouTube]