ATF: Bureau of Alcohol, Tobacco, Firearms, and Explosives. Investigates federal crimes that involve the manufacture or sale of firearms or explosives, acts of arson or bombings, and illegal trafficking of alcohol and tobacco products.

Bureau of Consular Affairs. Issues passports and responsible for the following matters in consulates, embassies and other territories around the world: deaths, arrests, robberies, adoption, citizenship, and travel.

CBP: Customs and Border Protection. Responsible for regulating and facilitating international trade, enforcing U.S. regulations, customs, and immigration. Includes the Border Patrol.

CDC: Center for Disease Control & Protection. Protects public health through the prevention of disease, illness, and disability. Particularly focused on the issues of infectious disease, food-born pathogens, and environmental hazards.

CIA: Central Intelligence Agency. Gathers information about foreign governments, corporations, and individuals, analyzes that information, and carries out covert activities overseas.

CS&C: Office of Cybersecurity and Communications. Responsible for the security and reliability of the nation's cyber and communications infrastructure (websites, online banking, etc.).

DEA: Drug Enforcement Administration. Combats drug smuggling and drug use. Also responsible for pursuing drug investigations outside the United States.

DSS: Diplomatic Security Service. Responsible for threat protection around the world, including both U.S. officials abroad and foreign officials visiting the United States.

DSS: Defense Security Service. In charge of security personnel investigations, industrial security, and security education, awareness, and training.

FAA: Federal Aviation Administration. Regulates and oversees all aspects of civilian air travel.

FDA: Food and Drug Administration. Protects and promotes public health through the regulation of food, tobacco products, dietary supplements, pharmaceuticals, vaccines, medical devices, cosmetics, etc.

FEMA: Federal Emergency Management Agency. Coordinates national response to disasters that occur in the United States and overwhelm local authorities.

FBI: Federal Bureau of Investigation. Investigates federal criminal activity, counterintelligence within the United States, and has jurisdiction over Native American reservations inside the U.S.

ICE: Immigration and Customs Enforcement. Responsible for identifying and removing vulnerabilities to the country's border, economic, and transportation infrastructure, as well as responsible for removing those illegally staying in the country.

NPS: National Park Service. Responsible for managing all U.S. national parks, as well as many important monuments.

NSA: National Security Agency. Manages worldwide monitoring, collection, decoding, translation, and analysis of information, including surveillance. Responsible for the security of the United States' information and communications.

TSA: Transportation Security Administration. Responsible for the security of the traveling public, including the Federal Air Marshal Service.

USMS: United States Marshals Service. Responsible for fugitive retrieval, prisoner transport, court security, and serving arrest warrants.

USSS: United States Secret Service. In addition to protecting national leaders (both present and past), also responsible for investigating financial crimes including counterfeiting and othre major fraud.

FSB: Federal Security Service of the Russian Federation. Successor to the KGB. The principal security agency of the Russian Federation, responsible for counterintelligence, internal security, counterterrorism, surveillance, and the investigation of serious crimes. Also a military service, like a combination of the United States' FBI, CIA, and Armed Forces all rolled into one.

INTERPOL: International Criminal Police Organization. Intergovernmental organization that facilitates international police cooperation. Intended to be as neutral as possible, so typically does not intervene or take action in connection with military, political, religious, or racial matters, although it does focus on - among other things - public safety, terrorism, organized crime, genocide, war crimes, piracy, art theft and trafficking, smuggling, human trafficking, money laundering, and white-collar crime.

Ministry of State Security. China's main security agency, responsible for counterintelligence, foreign intelligence, and political security. Also has the authority to act as regular police and arrest or detain people for crimes involving state security.

Mossad: Israel's national intelligence agency, responsible for intelligence collection, covert operations, and counterterrorism. Oversees The Kidon, an elite group of assassins.

SIS: Secret Intelligence Services. The U.K.'s intelligence agency, also known as MI6. Supplies foreign intelligence to the British government. While the "MI" (short for Military Intelligence) sections used to number nearly twenty, there are only two remaining: MI5 which deals with counterintelligence, and MI6, which acts as a liaison between SIS and Foreign Office.