htaccess aşağıdaki kodu düzenleyerek ekle...

RewriteEngine On
RewriteCond %{HTTP_REFERER} ^http://(.+\.)?izinverdigindomain1\.com/ [NC,OR]
RewriteCond %{HTTP_REFERER} ^http://(.+\.)?izinverdigindomain2\.com/ [NC,OR]
RewriteCond %{HTTP_REFERER} ^http://(.+\.)?izinverdigindomain3\.com/ [NC]
RewriteRule .*\.(jpeg|jpg|gif|bmp|png)$ /images/yasak.jpg [L]