One of the most serious problems with any blogging system, including WordPress, is that the comments area is wide open to that scourge of the Internet, spammers. In this case, it's comment spam.

Comment spam is created by people seeking to boost their Google rankings by having lots of links pointing to their own websites. This causes a wide variety of problems:

• When Google detects content spam, they will often block the site it's coming from because it messes up their ranking system.

• It takes up your valuable time and bandwidth to eliminate these posts.

• If the onslaught of spam is heavy enough, it may result in a denial-of-service attack, intended or not, which is a situation in which the server tries so hard to post bad information and/or deliver notification emails to you that it denies service to the legitimate requests. In at least one case, a blogger received over two thousand email notifications of comments that needed approval; as he dealt with these, he continued getting more, ultimately crashing his mail server.

As you can see, even if you have your comments set to post only upon approval, this can be a serious problem. One solution is the Akismet plugin for WordPress.

Akismet Plugin and Other Plugin Options for WordPress

Akismet is designed to help you filter out those nasty spammers, and it's not hard to get it installed into your WordPress system. Download the plugin, and upload it to the blog directory on your server in the plugins subdirectory under wp-content. Activate from the WordPress plugins menu. If you have a notice that you need the Akismet API, go to the WordPress website and look or ask for one.

Here's the magic: the only instruction in Akismet is "forget that spam was ever a problem." You don't have to do anything else at all – the spam will simply be bounced. You will not receive a notification, nor will you have to go out and delete spam.

Another plugin for eliminating spam from bots is the "Did You Pass Math" plugin. This one makes the user perform a simple math problem before submitting a comment. As most humans can handle this and most spambots can't, it's pretty likely that a comment posted through this is a legitimate comment. You should add a note of caution that your comments will be deleted if you answer the math wrong, though; a wise commenter will use an offline composition tool, not post directly to the comments area.

If This Still Doesn't Work

If you still can't eliminate spammers with these plugins, you can eliminate them by denying them access to your comments area. This does not mean you have to disable your comments section, only that you need to set up a filter.

It's not usually as simple as just blocking their IPs. Serious spammers use random IPs, while blocking IPs may get rid of them for a short time, it will ultimately prevent legitimate comments from being posted. Spammers are also notorious for hijacking other people's IP addresses. But as a short-term emergency solution, you can try it. The IP address is included in the information packet for the comment; it's similar to a traceable phone number. Look for clear patterns in your IP numbers.

Use the .htaccess file to block unwanted IPs from even seeing your blog. For instance, these lines can be added:

order allow,deny
deny from 123.123.123.123
deny from 456.456.456.*
deny from 789.789.*.*
allow from all

IPs are four-part numbers, such as 192.168.0.1. Typically, if you see a pattern with the first two sections being identical, you can block all IPs of that type by simply listing them as 192.168.*.*, as you see above. This screens out all these IP numbers. Blocked IPs will get a 403 error page; customize yours so that your contact details are listed in case you're blocking out a legitimate user. Don't use your regular email; a spammer can harvest that too, for a whole new set of problems. Instead, encode your email so that it's not automatically readable.

When you think you have your problems addressed, you can remove the block from your .htaccess file. If it still doesn't work, or if you don't see an IP pattern, it's likely that spambots are hijacking someone else's machine to attack your site. In this case, do not use the IP block.

Again, if you don't have an IP pattern of attack, this may not be worth doing. Remember, too, that with IP addresses, the first numbers affect the largest number of computers, like a reverse address: USA, California, Sacramento, X Building, Ste. 101, Joe Schmo. An IP follows roughly the same pattern, with the last of the four sections referring to the specific computer it is attached to.

Google's Nofollow Attribute

Of course, if it's a waste of their time to spam you, spammers may just skip you altogether. For this reason, you can use the Google Nofollow attribute for links: . This attribute is embedded automatically by modern versions of WordPress.

It does not eliminate links, which is what spammers are working on adding to your site. Instead, it makes those links irrelevant to Google. The end result is that it doesn't hurt your rank in Google, and it doesn't help a spammer to send data to your site. It also marks you, for spambots looking for an easy target, as a waste of time.

This is not an immediate fix. But it is a way to make your blog resistant to spammers in the future. If you're already a target, you'll have to work with it slowly, incorporating all these fixes. If you aren't a target, the very least you should do is turn on the nofollow option in your WordPress system; this will deter any hungry spambots. Upgrade your version, or look for one of the plugins that provides this service for you.