National Terrorism Advisory System

Bulletin 

www.dhs.gov/advisories DATE AND TIME ISSUED: May 15, 2017 11:30 P.M. EDT 

TIME 

b 

DURATION 

This Bulletin will expire on 

November 15, 2017 

at 12:00 a.m. 

Summary of Homegrown Terrorism Threat 

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. 

ADDITIONAL DETAILS 

 We face one of the most serious terror threat environments since the 9/11 attacks as foreign

terrorist organizations continue to exploit the Internet to inspire, enable, or direct individuals

already here in the homeland to commit terrorist acts. 

 Homegrown terror suspects are increasingly relying on technology, such as end-to-end 

encrypted social media applications, to avoid detection. Moreover, terrorist groups are 

urging recruits to adopt easy-to-use tools to target public places and events. Specific attack 

tactics have included the use of vehicle ramming, small arms, straight-edged blades or

knives, and homemade explosives, as well as other acts such as taking hostages. 

 As the United States steps up efforts to disrupt and defeat terrorist groups overseas, we will

continue to face a multi-faceted threat environment. 

 Specifically, continued successes aimed at disrupting and defeating terrorist groups overseas 

may encourage homegrown terrorists inside the United States to carry out acts of violence. 

 Additionally, foreign terrorist fighters, who have acquired training and battle-tested 

terrorism experience, are likely to flee from terrorist-controlled territories with a desire to 

conduct attacks elsewhere, including the United States. Some of these individuals may be 

U.S. citizens or citizens of other nations attempting to travel to the United States on visas, from visa-waiver countries, with the 

aim of attacking the homeland or inciting others within our borders to conduct attacks. 

TYPES OF ADVISORIES 

Bulletin 

Describes current developments 

or general trends regarding 

threats of terrorism. 

Elevated Alert 

Warns of a credible terrorism 

threat against the United States. 

Imminent Alert 

Warns of a credible, specific and

impending terrorism threat 

against the United States.

U.S. DOMESTIC COUNTERTERRORISM EFFORTS 

 DHS and the FBI continue to provide guidance to state, local, tribal and territorial partners related to the current threat environment. DHS

also partners closely with the private sector to provide risk assessments and coordinate security measures with business owners and

operators. The public may continue to observe law enforcement and security activity in and around public places and events. 

 DHS is taking steps to address the threat from foreign terrorist fighters who have traveled or attempt to travel to the United States,

including working closely with the FBI and Intelligence partners to identify U.S. persons who left the country to join terrorist groups, as

well as putting in place enhanced screening and vetting measures to detect travelers with potential terrorist connections. 

 More broadly, we remain committed to preventing violence and threats meant to intimidate or coerce specific populations on the basis 

of their religion, ethnicity, or identity, and we will seek justice against the perpetrators of such acts. 

HOW YOU CAN HELP

 Report suspicious activity to local law

enforcement who are best to offer specific

details on terroristic indicators. 

 Suspicious activity or information about a 

threat may also be reported to Fusion 

Centers and the FBI’s Field Offices - part of 

the Nationwide Suspicious Activity 

Reporting Initiative. DHS and FBI are 

especially interested in unusual foreign 

travel to known terrorist locations. 

 Learn how to recognize signs of preoperational planning associated with 

terrorism or other criminal activity. 

BE PREPARED 

 Be prepared for security and plan ahead. 

Anticipate delays and restrictions on items 

around populated places and at events. 

 Be responsible for your personal safety. 

Make a mental note of emergency exits and 

security personnel. Carry emergency contact 

and special needs info with you at all times. 

 Business owners are encouraged to 

Connect, Plan, Train, and Report to 

prepare businesses & employees. Security 

tools/resources can be accessed through 

the DHS’s Hometown Security Campaign.

 For more visit Ready.

If You See Something, Say SomethingTM. Report suspicious activity to local law enforcement or call 911. 

The National Terrorism Advisory System provides information on homeland security issues and threats. It is distributed by the Department of Homeland 

Security. More information is available at: www.dhs.gov/advisories. To receive mobile updates: www.twitter.com/dhsgov 

If You See Something, Say SomethingTM used with permission of the NY Metropolitan Transportation Authority.

STAY INFORMED 

 The U.S. Government will provide additional

information about any emerging threat as 

additional information is identified. The 

public is encouraged to listen to local law 

enforcement and public safety officials. 

 We urge Americans to continue to travel, 

attend public events, and freely associate 

with others but remain vigilant and aware of

surroundings. 

 The Department of State issues international 

travel alerts and warnings.

NTAS ADVISORY 2017.001-B