Easily apply comment moderation blacklist on registration and prevent spammers for registering on your WordPress site.
Common WordPress problem, when the registration is open a group of spammers registers on your site and start postings their content. One can stop this by editing function.php file and blocking the domains. There is one more easy option for blocking spams. Ban Hammer, a WordPress plugin simply uses comment moderation blacklist and prevents people from registering your site.
Other than creating its own tables in database, it pulls from your list of blacklisted emails using the Comment Blacklist feature, native to WordPress. Since emails never equal IP addresses, it simply skips over and ignores them. It simply means you only have ONE place to update and maintain your blacklist. When a blacklisted user attempts to register, they get error message that they cannot register. Error message is customizable (visit Dashboard -> Tools -> Ban Hammer).