5. Limit the amount of visible public information about you on networking sites such as Facebook, MySpace or LinkedIn by changing your privacy settings. You can make your profile available only to friends, choose not to have it indexed by search engines or block certain users (see How to maintain your privacy in Facebook).
6. If you've posted photos of yourself on Flickr or Facebook, you may wish to restrict access and not make them freely available to the world at large. You can allow only friends to view your photos, restrict certain albums, or remove your tag from photos your friends have posted.
7. If you like to post on discussion forums or leave comments on blogs, consider creating an online alias. Choose a username that can’t be linked to your real name or location and that doesn’t reflect an obvious passion. And when you do post comments, don’t give away revealing personal details.