From the Executive Summary: "The ideological threat of violent extremism is a global problem with domestic implications. Extremist groups conduct continuous communications campaigns, targeting vulnerable and receptive individuals to get them to self-radicalize and conduct violence in the name of extremist ideologies. As evidenced by Americans who have joined terrorist organizations or conducted mass casualty attacks, such as those witnessed in Orlando, Florida, and San Bernardino, California, the implications of violent extremist propaganda campaigns are becoming more complex, more widespread, and more deadly. The United States government (USG) currently spends billions of dollars each year to understand, communicate with, and engage various audiences, but its efforts in countering extremist propaganda remains fractured, uncoordinated, and inefficient. There have been numerous studies, reports, and reviews identifying problems and recommending solutions but no sustained success. There have also been attempts to enlist America's private sector to fight terrorism."
Office of the Director of National Intelligence: https://www.dni.gov/