It is a question that I get all the time, someone is frustrated that someone is bad mouthing them on social media, or around town to their friends, family or co workers. Free speech rights make it difficult to sue someone for bad mouthing you, but, not always impossible. You can sue someone for making knowingly false factual statements about you, it is called defamation. You can only sue for factual statements, statements of opinion are protected by the constitution, you cannot sue someone if they say you are a bad person, nasty, rude, etc. You can sue if they make a false factual statement, ie say that you are a sex offender when you have never committed a sex crime. You can do that even if you are what is called a public figure, a political leader or other high profile person, but, there are some different rules that apply when you are a public figure as opposed to a private citizen.