<p>Technological advances facilitate intelligent automated systems that are designed to help teams improve teamwork processes, e.g., communication in medical teams or simulated team training in aviation. To provide feedback, such systems constantly collect data, which can lead to privacy or security concerns of employees. Consequently, teams might perceive such systems as psychologically invasive, i.e., their privacy to be intruded. Previous work acknowledged that it is important to design unobtrusive systems, but empirical evidence on conditions under which teams accept electronic monitoring for teamwork support is missing. This work investigates psychological reactions to electronic team monitoring (ETM), i.e., automated systems that aim to support human teamwork. In study one, <i>N</i> = 156 participants watched one of three video vignettes in an experimental between-subject design. The vignettes presented ETM with varying levels of invasiveness. High invasiveness related to perceived unfairness, stress and lower acceptance. In study two, between-subject differences in reactions to ETM were investigated in a virtual team task with ad-hoc teams. <i>N</i> = 20 participants worked on a team task and were made believe that they are monitored for two different purposes (low invasive system for team support vs. high invasive system for performance appraisal). Teams did not differ regarding perceived acceptance or stress and both systems were rated as equally invasive. Teams questioned the validity of both ETM for supporting teamwork processes. The results of the studies demonstrate that invasiveness is decisive for teams’ reaction to ETM. To avoid team members’ resistance, the perceived invasiveness should be considered as a salient feature that might negate intended positive effects.</p>