This report, developed by the Office of Community Oriented Policing Services (COPS) and the Police Executive Research Forum, provides information on the use of social media in policing. The report is part of a series of publications covering emerging issue in policing. The first section of the report covers the use of social media platforms by law enforcement for the purpose of disseminating information to the public about crime issues, crime prevention programs, and police department activities. The remainder of the report discusses the use of social media for purposes other than the dissemination of information, such as preventing and investigating crimes, managing large gatherings of people, and handling other events. The experiences of individual agencies are included in the report's five chapters. Chapter 1 describes the experience of the Toronto Police Service as it developed a social media policy, while chapter 2 identifies intelligence considerations, including the various types of social media monitoring used by two units in the New York City Police Department. Chapter 3 outlines strategies to address robberies and other violent crime committed by flash mobs, as seen in three cities: Philadelphia, Minneapolis, and Milwaukee, while chapter 4 identifies the roles of social media during riots and violent social disturbances in the United Kingdom and Vancouver. The last chapter, chapter 5, describes the social media aspects of organized demonstrations and freedom of speech issues experienced by the Bay Area Regional Transit Police Department in San Francisco, CA, in 2011. Resources and appendixes