This chapter provides an analysis of the ethical issues that arise from the emergence of counter terrorism policies and practices related to social media and its use for terrorist purposes. Firstly, the chapter highlights the manner in which social media is exploited by extremists and terrorists. The chapter then analyses the evolving nature of the threat and the need for the state to engage with privately owned, for profit, technologies companies to undertake counter-terrorism activities, and the ethical issues this raises. The chapter then considers issues pertaining to the responsibilities of the state, and the role and purpose of private corporations in determining the boundaries of free expression; the limits of free speech within liberal democracies; and inequitable treatment of extremist material informed by different ideological frameworks. Throughout the analysis recognizes the constraints and limitations that the state faces in seeking to address social media based manifestations of extremist and terrorist propaganda and challenge this poses.