Police Department of Chicago v. Mosley, 408 U.S. 92 (1972), was a United States Supreme Court case which concerned freedom of speech under the First Amendment.

Municipal Code, c. 193-1 (i).When he saw a notice of the ordinance in a newspaper, Mosley called the police department, who advised him that he'd be arrested if he kept up his protest.

[2] The trial court sided with the city and issued a directed verdict upholding the ordinance, reasoning that it met the standards for a time, place, or manner restriction.

[2] Because the law could apply to circumstances where the city had not demonstrated any real reason to prohibit all peaceful protests (such as Mr. Mosley's), it prohibited speech more broadly than the constitution would allow: In the subject case where the sole question is right of access to a public way for the purpose of expression of views and where there is no danger of interference with a valid state interest, plaintiff's First Amendment right to picket may not be constitutionally denied.Chicago appealed the ruling to the U.S. Supreme Court.

Given what Chicago tolerates from labor picketing, the excesses of some nonlabor picketing may not be controlled by a broad ordinance prohibiting both peaceful and violent picketing.This opinion contains what would become an often-quoted statement about the First Amendment's strong protection for free speech:[4] But, above all else, the First Amendment means that government has no power to restrict expression because of its message, its ideas, its subject matter, or its content.Chief Justice Warren Burger wrote a short concurrence in order to state that, although he agreed with the majority on this case's outcome, "the First Amendment does not literally mean that we 'are guaranteed the right to express any thought...'"[1]