said by pnh102:Any person or entity in the USA can legally sue anyone else for
any reason, regardless of merit. Of course, such lawsuits can be declared frivolous or can be dismissed outright, but the burden of proof is on the defendant to prove that he/she is not liable. Of course, that means "lawyering up" and spending tons of money to defend oneself in court.
Someone else said this once, and it applies here perfectly... There's a reason it is called the "legal system" and not the "justice system."
Filing a frivilous suit in itself is actionable (meaning someone can be sued for filing a frivilous suit), and filing a blatantly frivilous suit could be contempt of court. Threatening to file a frivilous suit can (and has been prosecuted as) blackmail.