Add The Following code to a .htaccess file in your home folder.
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www.)?domain.com(/)?.*$ [NC]
RewriteRule .*.(gif|jpg|jpeg|bmp)$ – [F,NC]
In the example above be sure to replace domain.com with your actual domain name. This will stop other sites from hotlinking images that end in .gif, .jpg, .jpeg, and .bmp.
