“Fostering Freedom Online: the Role of Internet Intermediaries” is the title of a new title in the UNESCO Internet freedom series. With the rise of Internet intermediaries that play a mediating role on the internet between authors of content and audiences, UNESCO took a joint initiative, with the Open Society Foundations, the Internet Society, and Center for Global Communication Studies at the University of Pennsylvania’s Annenberg School for Communication, to examine this recent historical phenomenon and how it impacts on freedom of expression and associated fundamental rights such as privacy. The case study research, collaboratively delivered by 16 international researchers led by Ms Rebecca MacKinnon and Mr Allon Bar, as well as 14 members of International Advisory Committee, covers of three categories of intermediaries: Internet Service Providers (fixed line and mobile) such as Vodafone (UK, Germany, Egypt), Vivo/Telefônica Brasil (Brazil), Bharti Airtel (India, Kenya), Safaricom (Kenya), Search Engines such as Google (USA, EU, India, China, Russia), Baidu (China), Yandex (Russia) and Social Networking Platforms such as Facebook (USA, Germany, India, Brazil, Egypt), Twitter (USA, Kenya), Weibo (China), iWiW (Hungary). The research showed that internet intermediaries are heavily influenced by the legal and policy environments of states, but they do have leeway over many areas of policy and practice affecting online expression and privacy. The findings also highlighted the challenge where many state policies, laws, and regulations are – to varying degrees – poorly aligned with the duty to promote and protect intermediaries’ respect for freedom of expression. It is a resource which enables the assessment of Internet intermediaries’ decisions on freedom of expression, by ensuring that any limitations are consistent with international standards.