This paper aims at investigating the trends of usa case-law with regard to the protection of speech in the public interest, starting from Supreme Court’s Chaplinsky vs. New Hampshire of 1942. In this case and many followings until Snyder vs. Phelps of 2011, the opinion of the Court was in favor of the protection of speech in the public interest, even when it may cause offense to the majority of its intended audience. Among them the paper focuses on these main topics: the limitations of hate speech and their constitutionality in the context of First Amendment law; the nature of these limitations, discussing if they should be general and grounded on an system of values or concretized in specific cases of protection of honor and reputation; the relationship between direct and indirect regulations of the freedom of expression.