Hot linking not working

Thanks for such a great plugin!

After enabling the hotlink prevention function, all of the images I’ve found that are hot linked to on my site are showing up as broken links on the infringing sites (which is great!).

Except for one site which is hotlinking over 400 times to images on my site. I’m stumped as to how the plugin is preventing hotlinking to from the other sites but not this one particular site.

Any ideas?

I was considering using this code in the .htaccess instead and disabling the hotlink function in the plugin.

/* Prevent image hotlinking in WordPress */
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?yourwebsite.com [NC]
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?google.com [NC]
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?facebook.com [NC]
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?twitter.com [NC]
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?scoop.it [NC]
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?pinterest.com [NC]
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?quora.com [NC]
RewriteRule \.(jpg|jpeg|png|gif)$ – [F]

Is this a viable option? Or is there awaiting period before hotlinks to my images are broken?

Thanks