Precautions while using Social Networking Sites
Customize privacy options
Social networking sites increasingly give users more control over their own privacy settings. Dont assume you have to take whatever default settings the site gives you. Check out the settings, configuration and privacy sections to see what options you have to limit who and what groups can see various aspects of your personal information. Facebook probably has some of the broadest privacy options, giving you control where no one, friends, friends and networks, or everyone can see basic info, personal info, photos, friends and postings.