The concept of taboo words (cue the George Carlin tape) is culturally-dependent. I told the story elsewhere (when you get old, you repeat your stories), but one of my Korean vendors told me that Korean doesn't have taboo words, so those in Korea who are bilingual use the English ones when they need to blow off steam. Cussing: One of America's most in-demand exports.
"But I tell you that anyone who is angry with a brother or sister will be subject to judgment. Again, anyone who says to a brother or sister, ‘Raca,’ is answerable to the court. And anyone who says, ‘You fool!’ will be in danger of the fire of hell." -Matthew 5:22
Jesus's point is not that "raca" is the Aramaic equivalent of the F-bomb (the commentaries say it's closer to calling someone empty-headed); what is being highlighted is our practice of using our words to tear down one another (as the James 3:5-10 quote makes clear). It's not the word itself; it's the heart issue behind the words. And that issue crosses all languages and cultures.
And if you disagree with me, raca!