Couples might have been involved in erotomania, unrequited love, and revenge. They might have been involved in for-profit financial and professional gratifications resulting from private eye eavesdropping. Professional surveillance operatives, private eyes, eavesdroppers, and other invaders of personal space may revel in self-enhancing justification, and even praise and fame for their actions, which, in other contexts, would be judged amoral and/or punishable. Voyeuristic sexual stalkers, such as the protagonists in Rear Window and Peeping Tom, experience polymorphous perverse pleasure, particularly sadistic, by invading the privacy of their victims. The chapter explains the main psychoanalytic issues associated with every form of stalking. The psychological realities of stalking and the objective realities of stalking, hacking, bugging, peeping, tapping, eavesdropping, spying—all of the invasions of privacy related to the broader rubric, stalking—have real, objective effect on the workings of the psyche. Steven Spielberg’s film and directing debut, an original masterpiece on stalking, is Duel.