This chapter will focus on the involvement of Dark Tetrad personalities in cyberstalking and trolling. Cyberstalking refers to stalking using methods of electronic access and communication, such as hidden webcams, GPS devices, and SpyWare, to monitor the victim’s behavior and anonymous pursuit and contact using fake online profiles. First, the chapter will discuss the differences between stalking and cyberstalking. A review of the conceptual explanations for the involvement of Dark Tetrad personalities in cyberstalking and surveillance will follow this discussion. In the following section, the chapter will focus on cyber trolling and its association with Dark Tetrad personalities. Trolling behavior includes starting aggressive arguments and posting inflammatory, malicious messages in online comment sections to provoke, disrupt, and upset others deliberately. The chapter will review definitions and descriptions of cyber trolling. Theories about each Dark Tetrad traits motives for using trolling behavior will follow. The chapter will later present research findings on the relationship between the four dark personalities, cyberstalking, and trolling.