This paper presents a novel concept for personalized privacy support on large public displays. In a first step, a formative evaluation was conducted in order to analyze the requirements of potential users regarding the protection of private information on large public displays. The insights gained in this evaluation were used to design a system, which automatically adapts the information visible on public displays according to the current social situation and the individual privacy preferences of the user working on the display. The developed system was evaluated regarding its appropriateness for daily usage and its usefulness to protect privacy.