allow/deny external request htaccess

I want to block Flash/SWF uploaded by my users from calling other domains(unle开发者_运维问答ss approved).

I only want to block only a few domains in which I think is malicious.

---

# List the domains here, put [NC, OR] at the end of
# each domain rule except the last one.
RewriteCond %{HTTP_REFERER} example\.com [NC, OR]
RewriteCond %{HTTP_REFERER} example\.invalid [NC, OR]
RewriteCond %{HTTP_REFERER} example\.org
RewriteRule .*\.swf http://localhost [L,R=301]