Teacher use of social networking sites such as Facebook has presented some ethical dilemmas for policy makers. In this article, we argue that schools are justified in taking action against teachers when evidence emerges from social networking sites that teachers are (a) doing something that is illegal, (b) doing something that reflects badly on their strictly professional judgments and attitudes, or (c) pursuing or contacting students in a way that makes the students uncomfortable. Policies that ban teacher use of social networking are not justified, however, if teachers are simply engaged in highly controversial activities. As long as teachers take reasonable precautions to ensure that their online activities are not easily connected to students, schools, or their professional identities, they should be permitted a realm of privacy to express their individuality as human beings. If teachers are not engaged in harmful activities, open teacher involvement with social networking may provide productive educational possibilities. As we develop this argument, we attend to the various complexities that this ethical framework presents.