This plugin adds 2 form fields to the comment form (hidden by CSS) to detect spam bots that autofill all form fields they find
Recapture fights user registration spam by placing a reCAPTCHA on the user registration form.
SecureContact is a drop in form for users to contact you. It can be implemented on a page or a post. It offers enhaced security by using captcha image
This plugin will allow you to remove an unwanted author-URI entered by a commenter with one single click of your mouse.
WP Spam Hitman allows you to fight with spam using set of patterns and hitpoints. It also allows you to decide what’s going to happen to the spam
The plugin adds links to bloggers posts for readers to contact them without scripts or work-a-rounds like my email is john (at) doe.com.
Allows you to display a captcha on your comment form to avoid spam.
WatchMyBack24 is a powerful spamfighting plugin against comment or trackback spam.
A plugin that can be used to block or “ban” users via their IP address from viewing your blog, and then redirecting them to a URL of your choice.
Replaces the comment form with randomised field names to prevent automated comment spam.