No legitimate purpose means that you are acting the way you are to hound, frighten, intimidate, or threaten another person.  In other words, it is not enough that you were angry, or upset, or any number of other natural human emotions.  In fact, it’s not about your emotions, tone of voice, or body language at all. Rather, it must be proven you are doing these things specifically to hound, frighten, intimidate or threaten another person.