Name: Stop Hotlinking
Version: 1.1
Description: Denies any request for static files (images, css, etc) if referrer is not local site or empty.
Rules: 
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{REQUEST_URI} !^%relative_root%(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteCond %{HTTP_REFERER} !^%scheme%://%host%.*$ [NC]
RewriteRule \.(ico|pdf|flv|jpg|jpeg|mp3|mpg|mp4|mov|wav|wmv|png|gif|swf|css|js)$ - [F,NS,L]