本文聚焦於批判和反思社群媒體對當代社會帶來的挑戰與威脅。除了釐清關於「社群媒體」一詞的定義及其複雜意涵之外，本文以臉書為例，檢視社群媒體對當代社會的影響，包括社群媒體對民主社會構成的威脅、對新聞業和真相造成的衝擊、對隱私與個人資料的商品化、對弱勢群體施加的歧視，以及臉書作為全球最大數位平台的商業本質。為了防止臉書等社群媒體平台繼續對社會造成負面影響，並且提高其問責性、透明度和公共性，本文最後提出了有助於整個社會（而非社群媒體平台本身）的一些政策建議。

This article focuses on criticizing and reflecting on the challenges and threats that social media poses to contemporary society. In addition to clarifying the definition of “social media” and its complex implications, this article takes Facebook as an example to examine the impact of social media on contemporary society, including the threat posed by Facebook to a democratic society, its threat to the very survival of quality journalism and even the truth per se, its commodification of privacy and personal data, its discrimination against vulnerable and disadvantaged groups, and its corporate nature of being the world’s largest digital platform. In order to prevent social media platforms such as Facebook from continuing to do evil, and to improve their accountability, transparency and publicity altogether, this article proposes some policy options for the benefit of the society at large rather than the digital platforms.