"Since 2015, the Department of Homeland Security (DHS) has used this Bulletin to highlight the continuing threat from homegrown terrorists, many of whom are inspired online to violence by foreign terrorist organizations. The United States is engaged in a generational fight against terrorists, who seek to attack the American people, our country, and our way of life. An informed, vigilant, and engaged public remains one of our greatest assets to identify potential homegrown terrorists and prevent attacks."
U.S. Department of Homeland Security: http://www.dhs.gov/
National Terrorism Advisory System Bulletin (May 15, 2017)