Sedition - Through speech or writing, inciting or promoting discontent, resistance or rebellion against an organized government.In 1940, the Smith Act was passed, which made it a crime to advocate or to teach the desirability of overthrowing the United States Government, or to be a member of any organization which does the same. It was often used against Communist Party organizations in the 40's and 50's. In 1957 however, the Supreme Court ruled (in the case of Yates v. United States), that teaching an ideal, no matter how harmful it may seem, does not equal advocating or planning its implementation. Although unused since the 1960's, the Smith Act remains a Federal law.
As recently as 2005, a nurse at a New Mexico VA hospital was investigated by the FBI for sedition after writing a letter to the editor of a local newspaper, accusing several national leaders of criminal negligence. After the ACLU took up her case, the charges were dropped.