Some ways to deal with the smear campaign a borderline personality disorder sufferer may engage in. In effect, deal with it maturely.

From spreading lies about you to your relatives, friends, and acquaintances, to engaging in several tactics to make things as difficult as possible for you, your ex can become just as ominous and troublesome a presence in your life as he or she was when you were together.

Source: When Your Character Disordered Ex Defames and Makes Trouble for You – Manipulative-People.com