Comment Warning is a plugin for blogs that currently use a DoFollow plugin, or have used such a plugin in the past. It detects visitors arriving from URLs that indicate that they are likely to be potential comment spammers and ‘warns’ them of the blog’s comment policy.

Both the list of triggers and the message are customisable, allowing you to control who is shown the message and what they are shown.

The message is displayed via a JavaScript modal ‘popup’ (not a real popup). It is also shown as text to potential spammers who have JavaScript turned off (which is very unlikely).

Other Features

• Records visitors who have been warned, allowing you too see instances of warnings (in the Log).
• Allows you to navigate directly from the Log to the Edit Comments page for warned commentators IP address, so you can see any comments they’ve left.
• Allows you to see if a comment author has been warned, when browsing comments in the Admin panel.
• Allows you to see if a comment author has been warned when you get new comment and moderation required emails.

Demo

A demo is no longer available.

Redirection

It is possible to redirect potential spammers to a URL of your choice, either immediately (bypassing the warning) or after a certain number of potential spam visits from the same IP address. Note: the number of visits calculated only includes visits where a trigger is tripped (not if the same IP address visits your site via a different method) and does include page refreshes.

Where would you redirect them? Well this plugin was inspired by two people:

• RT Cunningham who until recently was redirecting potential spammers to a post asking them: Please Don’t Spam My Blog (post no longer available).
• Donncha O Caoimh who gives potential spammers the chance to Win a trip to Disneyland (by redirecting them there).

With this plugin in you can choose to send potential spammers anywhere you like! However, my personal view is that redirecting visitors is a little harsh, especially given that there may be some false positives.

False Positives

The default set of triggers have been chosen to be as ‘wide’ as possible, catching as many potential comment spammers as possible.

One side effect of this is that there may be some false positives. It is therefore not recommended to redirect users immediately. The default warning message acknowledges that false positives are possible and asks the user’s indulgence in reading the comment policy.

To limit false positives, the comment warning (or redirection) will not trigger for terms that are in both the refering URL and in your page’s URL. If you have a post with dofollow in the URL and a visitor arrives from another site with dofollow in the URL, there is a decent chance that they are not a spammer.

Requirements

WordPress 2.7+ (not tested on older versions).

Compatibility – WP Super Cache

I suspect that this plugin will NOT be compatible with WP Super Cache at this point. I will be doing some testing in the near future and, if necessary, changing the plugin so it does work with WP Super Cache.

I’m unaware of compatibility issues with any other WordPress plugin, but please let me know if you find any.

Installation

• Download the plugin file and unzip it.
• Upload the comment-warning folder to the wp-content/plugins folder.
• Activate the Comment Warning plugin within WordPress.

Support

This plugin is not supported.

Acknowledgements

This plugin builds upon code from the following sources:

• RT Cunningham’s How to Reduce AdSense Impressions while Improving CTR post.
• Donncha O Caoimh’s Win a trip to Disneyland post.
• Donncha O Caoimh’s Comment Referrers plugin.