Since 2007, social media platforms have become an important channel for information exchange among survivors, volunteer organizations, and nongovernmental organizations during emergencies and disasters. This chapter highlights the use of social media by emergency management agencies (EMAs), using multiple case study analysis. Each case represents county-level emergency management agencies that use Twitter to communicate to the public. The chapter discusses the benefits and disadvantages emergency managers face using social media. The use of social media platforms by emergency management is important because of their growing adoption among emergency management agencies and the general public. The term "social media" will refer to Internet-based platforms created to socially connect users via postings, followings, videos, and/or trending topics. Prior to 2007, many emergency management–related agencies did not use social media. Some of the first studies on the use of social media during emergencies were following the Virginia Tech shooting in 2007 and the Southern California wildfires in 2007.