The only problem with this modification is that it will only block anyone using the IPS addresses from those sites. It won't block IP addresses if those site users have personal IP addresses from their ISP. I ran into a problem where I had users from another website posting slanderous comments on my website and trying to steal my members. While I banned the members who posted their crap, I realized that banning the website that was trying to steal my members wouldn't work. You would need the actual IP addresses that is being used by the member trying to access your site. While it sounds like a good idea, it's only effective if you know the IP address of the user who is trying to access your website. When I ban someone from my site, I ban them via the ACP of the IPS software but also from the control panel that I use to edit files on the server where my site is hosted. It's a good idea to not only ban the username, but also their IP address and their email address.
