RewriteEngine On
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://([a-z0-9-]+\.)*reality-boards.net.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://([a-z0-9-]+\.)*partial-eclipse.net.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://([a-z0-9-]+\.)*the-prophecy.net.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://([a-z0-9-]+\.)*mayitbe.co.uk.*$ [NC]
RewriteRule .*\.(gif|GIF|jpg|JPG|zip|ZIP|bmp|BMP|png|PNG|mp3|MP3)$ - [F]

<Files .htaccess> 
order deny,allow 
deny from all 
</Files>