First, check the message box or comment area of the social networking site and print copies of all harassing content or inappropriate messages -- especially those that threaten to hurt your daughter. Report these incidents to the social networking site. If the problem persists, contact your local authorities and provide as much information as possible about the alleged bully. If you know that the harasser goes to your daughter's school, also consider involving school officials, such as the principal. And until the issue is resolved, you should consider the very good idea of removing your daughter's profile from the site.