United Nations Office for the Coordination of Humanitarian Affairs – Hashtag Standards For Emergencies – OCHA POLICY AND  STUDIES SERIES – THINK BRIEF, October 2014 | 012

“In recent years, social media tools such as Facebook, Twitter, Instagram, YouTube and blogs have demonstrated significant value during emergencies as the “information currency of disasters”. These digital tools give affected communities a flexible information platform to share local knowledge, transparently document efforts crowd-verify or eliminate false rumours, and engage in two-way communication with formal emergency response agencies. Twitter is currently the social media platform best suited for emergency response due to real-time post ing, public feeds and asymmetric relations (one-to-many or non-reciprocal information exchange). Facebook users comprise 82 per cent of the global social media market aged 16-64 outside of China, but privacy settings limit its use during a disaster.28 Other social media tools are used for emergency preparedness and response (e.g., YouTube), but there is less evidence-based research supporting their uptake during a crisis.”