<P> The opinion's most famous and most often quoted passage was this: </P> <Dl> <Dd> The most stringent protection of free speech would not protect a man in falsely shouting fire in a theatre and causing a panic . (...) The question in every case is whether the words used are used in such circumstances and are of such a nature as to create a clear and present danger that they will bring about the substantive evils that Congress has a right to prevent . </Dd> </Dl> <Dd> The most stringent protection of free speech would not protect a man in falsely shouting fire in a theatre and causing a panic . (...) The question in every case is whether the words used are used in such circumstances and are of such a nature as to create a clear and present danger that they will bring about the substantive evils that Congress has a right to prevent . </Dd> <P> The phrase "shouting fire in a crowded theater" has since become a popular metaphor for dangers or limitations of free speech . </P>

The first u.s supreme court case to address the issue of whether