Psychotherapy and counselling services are now available on-line, and expanding rapidly. Yet there appears almost no ethical analysis of this on-line mode of delivery of such professional services. In this paper I present such an analysis by considering the limitations on-line contact imposes on the nature of the professional-client relationship. The analysis proceeds via the contrast between the face-to-face case and the on-line case. At the core of the problem must be the recognition that on-line interaction imposes a physical barrier largely permitting only those disclosures of self we choose to make available, and greatly restricting the range of involuntary features and behaviours. I show why this is problematic, first, for the development of a close professional-client relationship, with particular emphasis on such failures as diagnosis and monitoring of the patient. Second I describe the importance of the development of professional character, and of how the on-line environment fails to provide a context for such character traits to emerge and develop.