Programs: Lock up your servers against Fusker

[Wenchy]

Okay, so can someone answer a couple of questions for me, please?

First, I'm working under the assumption that this code...

RewriteEngine on
# leave this line in allow empty referrers, remove to disallow empty referrers
RewriteCond %{HTTP_REFERER} !^$ [NC]
RewriteCond %{HTTP_REFERER} !^http://(.*@)?([a-z0-9-]+\.)*yourdomain\.com(:[0-9]+)?(/.*)?$ [NC]
RewriteCond %{HTTP_REFERER} !^http://(.*@)?1\.2\.3\.4(:[0-9]+)?(/.*)?$
RewriteRule .*\.(asf|mpg|mpeg|wmv|avi|rm|gif|jpeg|jpg|zip)$ - [NC,F,L]

...is the recommended .htaccess for anti-fuskering my domains? I can/should repeat this line...

RewriteCond %{HTTP_REFERER} !^http://(.*@)?([a-z0-9-]+\.)*yourdomain\.com(:[0-9]+)?(/.*)?$ [NC]

... for each of my domains that I want included.

Second, the code that grandmascrotum put up there a couple of posts... I heard somewhere that that huge string can actually put a load on your server each time a page, any page, is loaded. Any truth to that rumor? And, assuming the rumor is false, is there any clear evidence that using that "collection" in my .htaccess actually does any good these days?

Thanks