Civil Support: DOD Needs to Clarify Its Roles and Responsibilities for Defense Support of Civil Authorities during Cyber Incidents, Report to Congressional Committees [open pdf - 699KB]
"Cyber threats to U.S. national and economic security are increasing in frequency, scale, sophistication, and severity of impact. The Department of Defense's (DOD) 2013 Strategy for Homeland Defense and Defense Support of Civil Authorities (DSCA) states that DOD must be prepared to support civil authorities in all domains--including cyberspace--and recognizes that the department plays a crucial role in supporting a national effort to confront cyber threats to critical infrastructure. House Report 114-102 included a provision that GAO [Government Accountability Office] assess DOD's plans for providing support to civil authorities related to a domestic cyber incident. This report assesses the extent to which DOD has developed guidance that clearly defines the roles and responsibilities for providing support to civil authorities in response to a cyber incident. GAO reviewed DOD DSCA guidance, policies, and plans; and met with relevant DOD, National Guard Bureau, and Department of Homeland Security officials. […] GAO recommends that DOD issue or update guidance that clarifies DOD roles and responsibilities to support civil authorities in a domestic cyber incident. DOD concurred with the recommendation and stated that the department will issue or update guidance."
Government Accountability Office: http://www.gao.gov/