make a file called .htaccess & add the following then upload to your root dir
Code:
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^http://ServerIP/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://ServerIP$ [NC]
RewriteCond %{HTTP_REFERER} !^http://YourSite.org/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://YourSite.org$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.YourSite.org/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.YourSite.org$ [NC]
RewriteRule .*\.(jpg|jpeg|gif|png|bmp|zip|rar|mpg|mp3)$ http://www.SomeOtherSite.org/Theif.gif [R,NC]
The RewriteRule Are the extensions you want protected