"Social media sites have become useful tools for the public and law enforcement entities, but criminals are also using these sites for wrongful purposes. Social media sites may be used to coordinate a criminal-related flash mob or plan a robbery, or terrorist groups may use social media sites to recruit new members and espouse their criminal intentions. Social media sites are increasingly being used to instigate or conduct criminal activity, and law enforcement personnel should understand the concept and function of these sites, as well as know how social media tools and resources can be used to prevent, mitigate, respond to, and investigate criminal activity. To ensure that information obtained from social media sites for investigative and criminal intelligence-related activity is used lawfully while also ensuring that individuals' and groups' privacy, civil rights, and civil liberties are protected, law enforcement agencies should have a social media policy (or include the use of social media sites in other information-related policies). This social media policy should communicate how information from social media sites can be utilized by law enforcement, as well as the differing levels of engagement--such as apparent/overt, discrete, or covert--with subjects when law enforcement personnel access social media sites, in addition to specifying the authorization requirements, if any, associated with each level of engagement. These levels of engagement may range from law enforcement personnel 'viewing' information that is publicly available on social media sites to the creation of an undercover profile to directly interact with an identified criminal subject online. Articulating the agency's levels of engagement and authorization requirements is critical to agency personnel's understanding of how information from social media sites can be used by law enforcement and is a key aspect of a social media policy" (p. 1-2).