How to permanently block someone from your blog?

Someone asked me this question the other day — how do I ban a troublesome visitor permanently? The answer to this isn’t simple and requires some social engeneering of sorts which will also be dependent on how smart that visitor is.

Here are some fairly simple steps to ban someone from your blog. These steps assume that you control your hosting account and runs WordPress as your blogging tool.

• Require registration before commenting. This *might* hinder your visitor from commenting if he needs to sign up first and validates his email address with that. However, the troublesome visitor can always sign up for a new email address for the sole purpose of registering on your blog.
• If they were able to bypass step #1, you can change their password in the WP Admin. However, the visitor can always use the Forgot Password facility to retrieve it. A better trick would be to change his username instead so even if he’ll use the forgot password feature, he’ll have to do some pretty darn guesswork what his new username is. To get around it, the visitor will have to get a new email account and re-register on your blog.
• Together with steps #1 and #2, you can set all comments to stay in moderation first (see WP Options) so you’ll have to manually approve each comment before they show up and thus filtering out your visitor’s undesirable comments.
• IP ban him. In your hosting control panel (e.g. cPanel), there’s a feature there call IP Ban list. Identify your visitor’s IP address via one of his older comments and add it to the IP Ban List. If you’re lucky enough, your visitor might have a static IP address so he can’t visit your blog/site and leave a comment. The problem here is if the visitor is on a dynamic IP and he gets a fresh new one every he logs online. You can ban an entire IP range of his ISP but that would include other innocent potential readers as well.

A combination of any or all of the steps above might discourage your visitor to keep coming back and post a comment. Another idea I had was to sniff out the visitor’s browser version, OS and screen size and create an htaccess rule to redirect anyone with that combo elsewhere. The most effective method really is to totally disable commenting in your blog. :D

You guys have any other tricks in mind? I’m sending this link to the person who asked for advise so she can read your additional comments as well.