The study of sexual boundary violations, through the actual evaluation and treatment of therapists who have engaged in sexual misconduct, reveals that all of us are potentially vulnerable to violations of this nature. A number of lessons can be learned from the detailed examination of these cases. These lessons include the following: (1) There is a difference between the conscious and unconscious intent of the therapist. (2) "Love" in the therapeutic setting is fraught with problems, including the fact that it is often used as a defense against the therapist's own aggression. (3) Supportive therapy and boundaryless therapy often become confused when a therapist switches from an expressive to a supportive approach. (4) The thoughts, feelings, and behaviors that a therapist would most like to keep secret from a supervisor or consultant are the most important issues to discuss with that supervisor or consultant. These observations have a number of implications for prevention. Matters of technique are inevitably conflated with issues of ethical principles so that the teaching of ethics must include discussions of transference, countertransference, and the use of third parties, such as supervisors or consultants, to assist the therapist in the monitoring of professional boundaries.