Yes, at times we do limit First Amendment freedoms. While the text of the First Amendment references that “Congress shall make no law,” there are some limited types of speech that do not receive free-speech protection. Justice Oliver Wendell Holmes famously expressed this point when he wrote that “the most stringent protection of free speech would not protect a man in falsely shouting fire in a theatre and causing a panic.” Holmes’s famous phrase means that not all forms of speech are protected. For example, the First Amendment does not protect obscenity, child pornography, true threats, fighting words,
incitement to imminent lawless action, criminal solicitation or defamation.