This article describes results of a study investigating the potential of using social network analysis to evaluate programs that aim at improving schools by fostering greater collaboration between teachers. The goal of this method is to use data about teacher collaboration within schools to map the distribution of expertise and resources needed to enact reforms. Such maps are of great potential value to school leaders, who are responsible for instructional leadership in schools, but they also include information that could bring harm to individuals and school communities. In this article, the authors describe interview findings about concerns educators have with collecting and sharing social network data. A chief finding is that although the majority of teachers consider collecting social network data to be problematic but feasible, some teachers report concerns about privacy and the effect on their school's goals to foster community if the data are shared with their schools. (Contains 2 tables, 2 figures and 1 note.)