I cannot believe I just created an account to post about this; but... Maybe it is my law school training but nothing annoys me more when people threaten lawsuits with not even an ounce of understanding what they are talking about.
First I doubt this person even understands the legal definition of harassment. Granted I am making an assumption that this person is in the United States. Therefore, harassment defined in the easiest of terms: is the act of continued and regular unwanted actions against a victim. This may include anything from racial epithets to annoying or malicious remarks, but must become a pattern in order to qualify as harassment. Harassment is illegal and a victim can file for a restraining order against the perpetrator. Please note that this could have a different legal definition outlined by your State or country.
Whilst online harassment: may involve threatening or harassing emails, instant messages, or posting information online. It targets a specific person either by directly contacting them or by disseminating their personal information, causing them distress, fear, or anger. Whilst cyberstalking is a type of online harassment that involves using electronic means to stalk a victim, and generally refers to a pattern of threatening or malicious behaviours. All states have anti-stalking laws, but the legal definitions vary. Some state laws require that the perpetrator make a credible threat of violence against the victim. Others require only that the stalker’s conduct constitute an implied threat.
You would have to be able to show a continued and sustained "attack". But please note that someone telling you their opinion of you is not harassment. And it might be noted that everyone has the defence of the truth. This is mainly used in slander/libel cases but can be easily used in this context given the right circumstance.
