This brief serves to educate readers about the sovereign citizen movement, presenting relevant case studies and offering suggestions for measures to address problems caused by this movement. Sovereign citizens are considered by the Federal Bureau of Investigation (FBI) to be a prominent domestic terrorist threat in the United States, and are broadly defined as a loosely-afflicted anti-government group who believes that the United States government and its laws are invalid and fraudulent. Because they consider themselves to be immune to the consequences of American law, members identifying with this group often engage in criminal activities such as tax fraud, "paper terrorism", and in more extreme cases, attempted murder or other acts of violence. Sovereign Citizens is one of the first scholarly works to explicitly focus on the sovereign citizen movement by explaining the movement's origin, interactions with the criminal justice system, and ideology.