"This document focuses on the social media component of real-time and open source analysis (ROSA). ROSA is the process conducted by law enforcement and analytic personnel to (1) develop or enhance criminal intelligence (including situational awareness reports), (2) support a criminal investigation, or (3) identify public safety risks either past, present, or anticipated. During the ROSA process, law enforcement and analytic personnel gather publicly available information (otherwise known as open source) via social media resources and tools for analysis to determine whether criminal activity is occurring to support a criminal investigation or to assess risks to public safety and security. For purposes of this guidance, references to 'social media' include only publicly available information derived from social media sites. The document is not intended to cover legal or policy issues related to accessing private social media information."
California State Senate Joint Legislative Committee on Emergency Management: http://emergencymanagement.senate.ca.gov/