Social networking sites are interactive websites designed to build online communities for individuals who have something in common--an interest in a hobby, a topic, or an organization--and a simple desire to communicate across physical boundaries with other interested people. These sites are not unlike the old-fashioned "party line" telephones, but they leave a more permanent record of the conversations. The introduction of online social networking has created a cultural shift related to the idea of privacy: some people today are willing to expose more about themselves. Although social networking technology can benefit teachers, recent reports in the media have shown teachers being reprimanded for what school districts consider "inappropriate activity." In this article, the authors urge educators to consider the potential outcomes before they post. (Contains 23 notes.)