In 1997, the Supreme Court ruled in Reno v. ACLU that the federal Communications Decency Act (CDA) is an unconstitutional restriction on free speech. The law made it a crime, punishable by up to two years in jail and/or a $250,000 fine, for anyone to engage in online speech that is “indecent” or “patently offensive” if the speech could be viewed by a minor. The ACLU argued that the censorship provisions were unconstitutional because they would criminalize expression protected by the First Amendment.”]
Source: https://www.aclu.org/cases/reno-v-aclu-challenge-censorship-provisions-communications-decency-act