Anti-spam check the robots by behavior. No captcha. Antispam let robots do so as a human can't do.

(4)

This plugin utilizes reCAPTCHA to help your blog stay clear of spam-registrations.

(4)

Contact Form 7 Manual Spam Blocker is an easy-to-use plugin to block all those spammers who manually fill out forms on your website.

(4)

Сaptcha generated numbers and latin characters. Designed for use in custom forms and displays a simple shortcode, and connect to log form.

(4)

REPLACEMENT of the original Simple Trackback Validation Plugin from Miachel. Performs a simple but very effective test on all incoming trackbacks in o …

(4)

Scientifically proven by research from the University of Wollongong as the most secure text-based 3D CAPTCHA available -- on the most simple settings.

(4)

Simple question that blocks most spambots (and paid robots) by making them answer a common sense question

(4)

BuddyPress - Validate XProfile data with PCRE regular expressions.

(4)