Should we rethink the Human Right to Freedom of Expression [HRFE] in the age of social media? In this thesis I have reevaluated the philosophical foundation of the HRFE in how it is applicable to Facebook. I argue that the traditional Millian account of freedom of expression [FE] can ground a contemporary HRFE integrating all forms of expression, media, and public discourse in contemporary liberal democratic society, including social media. The problem is that social media like Facebook on some essential points do not meet the traditional conditions for FE. I argue that large platforms for expression like social media should meet these conditions. I then hint to some ways in which we could seek to harmonize social media with the traditional account of FE. The philosophical contribution this thesis purports to make is to create awareness that current "online" expression is divorced from our traditional "offline" conception of FE and that this harms liberal democratic legitimacy. The way forward I see to establishing a philosophical account of an integrated HRFE, is by taking as a point of departure that it should be grounded in offline society and its national identities. Then, issues concerning identity, conceptions of harm, and how to account for globalized online communication can be addressed as extensions and adaptations of the traditional account, adjusted to contemporary society. To achieve this, society should stop the self-regulation of tech companies and allow national governments some regulation of online expression to include it in the protection of an integrated HRFE.