My friends ex husband facebooked me accusing my friend of doing illegal things in her business. My friend has had problems with him before and they had a nasty divorce and custody battle. My friend wants to file harassment charges against her ex husband. Can she do that when I am the one he contacted. Also will I be involved if she does file harassment against him.

One post is not harassment. It is also not slander/defamation if he believes what he says OR if no one believes him.