There is one things that most new WordPress users want to do after few days: Block WordPress Comment Spam
You will understand after your site has been running for a couple of days.
Comment spam is a black-hat tactic to getting back-links to a website. Most of those fake comments are done via spam-bots (small programs) that inject comments into the comment field of your blog articles. Others are done by outsourcing this back-linking to cheap foreign countries like India or The Philippines.
The worst kind are comments are those that send you or your visitors to mall-ware sites.
Ways to Filter WordPress Comment Spam
There are a few ways to get rid of those pesky spam comments.
Uncheck the option that people can leave comments on your blog, very effective but not really visitor friendly. Go to Settings -> Discussion -> Uncheck all first three options.
Install Anti-Spam plugins to check if its a known spam comment so that the comment is put in the Spam reaction queue.
Install a anti spam bots plugin, that will block the comment bot and prevent the comment from coming into your WordPress system.
Set some rules in the Discussion section to make sure those WordPress spam comments are moderated before they hit your visitor facing site. Is always good to moderate your comments. One tip: Trust nothing, check and double check.
Set the option that people need to register before they can comment, however this will drive off some legit visitors that want to comment as well.
An important sign of a WordPress comment spam is to check if the comment is really on topic and will have good value for you or other visitors.
If not? Delete it. No sure? Copy the comment and search it in Google between quotes. If it shows the extract term on several hits, delete it.
Anti-Spam Plugins for WordPress
The number one plugin used for fighting off comment spam is Akismet.
Akismet is installed with any new WordPress site by default. After activation you need to register for an API Key at http://akismet.com
Please make sure you read their Terms of Services so you can make a good choice on what plan you should pick.
If you only use Akismet on a personal non-business blog with under 20.000 visitors per month you can select the personal plan and slide the price slider to 0.
Note: This plugin costs $5 a month (per site) if you make any money from your site, such as through an affiliate link, ad, or paid service.
After you activate the Akismet plugin you follow the notification and put in your key.
Cookies for Comments
The cookies for comments plugin will first set a cookie on a random URL that is then checked when a comment is posted. If the cookie is missing the comment is marked as spam.
If its a spambot that tries to place a cookie, it will fail as they won't accept that cookie.
You can find the plugin here http://wordpress.org/extend/plugins/cookies-for-comments/
Growmap Anti Spambot Plugin
This plugin is my favorite. It blocks spambots by adding a client side generated checkbox asking the comment author to confirm that they are not a spammer. (Like you see on this website)
A check is made that the checkbox has been checked before the comment is submitted so there's no chance that a comment will be lost if it's being submitted by legitimate human user.
Given your visitor the option to just tick a checkbox is much more user friendly than a Chapta (which are sometimes very hard to read) or do some calculation.
You can find the plugin here http://wordpress.org/extend/plugins/growmap-anti-spambot-plugin/
After you installed and activated the plugin go to Settings -> G.A.S.P to verify that the basic options are set or you want to change some text. You can configure extra checks like the number of links in a comment or the number of words in the commenters name field.
Combining Anti Spam Plugins
For me a combination of Cookies for Comments and Growmap Anti Spambot Plugin has reduced the number of spam comments to almost zero, maybe two or three manual spam comments, but that's it.
Giving me more time to build sites and write articles on my own sites.
So how about you? Does your website still gets loads of spam comments?