"You have heard that it was said to the people long ago, 'Do not murder, and anyone who murders will be subject to judgment.' But I tell you that anyone who is angry with his brotherwill be subject to judgment. Again, anyone who says to his brother, 'Raca,' is answerable to the Sanhedrin. But anyone who says, 'You fool!' will be in danger of the fire of hell. (NIV)
I figure Raca is the equivalent of "F-you!" Whenever someone said a wordy dird, most Christians that I know go nuts. It's almost as if the person had commented the unpardonable sin by using a four letter word and we as Christians generally make a value judgment of the character of the person that used the word. If I read the passage right, it is not the word choice that is important, but rather the intent of the speaker and the way words are meant to be received. People in general and Christians in particular have become very skilled treating people like garbage without using the magic words as if the magic words are missing then the words don't hurt.
I spoke a professor at college about my thoughts and he said I was right, but that he chose not to swear because it made a person sound unintelligent. I have also learned that some people swear because they have learned that language pattern from birth, but that doesn't indicate anything about the character of the person, rather that their word choice is appropriate to their upbringing and culture.
I guess my point is that you can not tell anything about someone's character by their vocabulary. One has to consider their actions and the intent of their words. Also that we can be meaner to each other than we pretend to ourselves.