Many words are intended to be hurtful. They should not be punished by law, just by people's contempt. To say words should be punishable by law takes you down a very dangerous path indeed and is against everyone's interests, because to stop our speech is to stop our thoughts.
"I do not agree with what you have to say, but I'll defend to the death your right to say it." --Voltaire.
All words are empty, because they don't directly do physical harm to someone. I agree it's cowardly and wrong, but not everything that's cowardly and wrong should be a crime. Sometimes you have to sit back and think "hang on, is this a dangerous infringement on personal liberty and free speech?"
The answer is "yes."