A recent report from edWeb.net, School Principals and Social Networking in Education: Practices, Policies, and Realities in 2010, shows how involved principals are in social-networking sites vs. teachers and librarians and how they see such sites working to improve schools.
Principals Were Less Likely Than Teachers or Librarians to Have a Social Network
Question: Social networks are growing rapidly in popularity. Are you currently a member of or have you ever joined a social-networking website like Facebook, MySpace, Ning, LinkedIn, or one of the social-networking websites created for educators (e.g., We Are Teachers, edWeb.net, etc.)?
Answer:

SOURCE: edWeb.net
An Overview of Principal Awareness of Social-Networking Websites
Results for principals who have joined one or more social networks:

SOURCE: edWeb.net