The development of new technologies that have emerged since the mid-1990s has led to Internet-based applications known as "social media" that enables people to interact and share information through media that were non-existent or widely unavailable 15 years ago. Examples of social media include blogs, chat rooms, discussion forums, wikis, YouTube Channels, LinkedIn, Facebook, and Twitter. Social media can be accessed by computer, tablets, smart and cellular phones, and mobile phone text messaging. This book explores how social media has been used by emergency management officials and agencies with a focus on examining the potential benefits, as well as implications, of using social media in the context of emergencies and disasters.