The Hollywood Reporter helps us out here:
Barring trademarks that include immoral or scandalous language is an unconstitutional restriction of free speech, the United States Court of Appeals for the Federal Circuit ruled Friday.
Eric Brunetti founded the fuct clothing brand in the 1990s, but decades later was denied a trademark for the label because the U.S. Patent and Trademark Office found it violated the Lanham Act's ban on immoral or scandalous matter.Here it might be useful to point out that according to the Urban Dictionary, the word "fuct" is the past tense of "fuck" in urban slang. The Reporter goes on:
Brunetti then took his case to federal court, arguing that fuct isn't vulgar — but, even if it was, barring immoral marks is unconstitutional.
The federal circuit agreed with him on the second argument — which wouldn't have been possible until June, when the U.S. Supreme Court overturned case law that held restricting someone's right to have a trademark didn't necessarily restrict that person's free speech. In that case, involving rock band The Slants, the court found the USPTO’s denial of trademarks had a chilling effect on speech.
While the court finds the use of vulgar trademarks in commerce discomforting, it acknowledges that similarly offensive images and words have secured copyright protection.In short, the courts have consistently held that even "discomforting" words enjoy full First Amendment protection.