: We argue that technical features which make aspects of computer network visible can have ambivalent effects for the users. On the one hand they support cooperation among the users, whereas on the other hand these features can be applied to control the users extensively. To examine this ambivalence we present the results of an empirical field study on the usage of networks´ visibility. Based on these findings we develop organizational and technical proposals for the application and design of features of visibility which could partly resolve this ambivalence. Keyword Codes: H.5.3, H.4.1, K.4.3