In which landmark case did a unanimous court rule that speech posing a "clear and present danger" especially during wartime may be surpressed

Clear and present danger was a doctrine adopted by the Supreme Court of the United States to determine under what circumstances limits can be placed on First Amendment freedoms of speech, press, or assembly. ... In that case, the Court considered the clear and present danger test, but rejected it as too mechanical and ...

¿cuál es la foto? ‍♀️