If we’re not careful we can all have unethical behavior that demeans others. For example, if you speak in a patronizing vocal tone, if you scream at the less powerful, or if you touch people inappropriately, you are engaging in unethical nonverbal communication. If you respond to others' communication in a way that misrepresents how you actually feel, you are being unethical. If you laugh at a racist joke even though you dislike it, your behavior is unethical both because it derogates others, and because it misrepresents your true reaction to the joke.
Nonverbal behaviors reflect your real attitudes, beliefs, and feelings. Without being aware of it we could be using our nonverbal behavior to intimidate, coerce, or even silence someone. Always try to remember that you are just as responsible for your nonverbal communication as you are for your verbal communication. I think if you do this you will make better and more ethical choices.