Mainstream media all over the world have been regulating the behavior of their journalists in social media, fearing these new forms of communications might damage the credibility of their institutions. Those who have not yet done so face with concern this unstoppable challenge and are now outlining their own guidelines for social media policies. In an effort to inspire the design of these new policies, this paper aims to approach the recurring topics in the policies already written by leading media such as AP, American Society of News Editors (ASNE), BBC, Bloomberg, Charlotte observer, Freedom communication, Los Angeles times, NPR, Orlando sentinel, Politico, Reuters, Rockford register star, Saint Louis post-dispatch, Source media group, The Denver post, The guardian, The journal gazette, The Manhattan Mercury, The New York times, The Roanoke times, The Wall Street journal y The Washington post. A qualitative content analysis of 22 of these policies has been conducted to identify these topics. [ABSTRACT FROM AUTHOR]