Antibot is a free wordpress plugin that blocks all kinds of bad bots crawling your website.
Block bots without annoying captchas. Cache friendly solution with rotating keys! Blocks comment, registration, and bbpress spam. Activate and done!
NURCaptcha inserts a reCAPTCHA on the Register Form of your site to protect it against spambots.
Ban users by IP, IP Range, host name, user agent and referrer url from visiting your WordPress's blog.
Block Semalt from crawling your website.
The most advanced protection against sploggers and spam users registration, is fully WordPress,WordPress MU ,BuddyPress and bbPress 2.0 compatible
Simply uses the HTTP_REFERER to determine if it's from 'Semalt', and blocks it with a nice 403 "Unauthorized" response.
Anti-Captcha is a transparent spam solution that does not require any end-user interaction.
Adds some extra security to your WordPress with only one click.
WP Engine has a custom 404 page for bots. This plugin removes that customization.
This plugin adds a new form of captcha to your Buddy Press registration and comment forms.
Use this plugin to prevent bots from spamming your website
Stop your WordPress website from being spammed by bots and restrict it only to humans.
Keep Your Site Happy, add Khush Captcha Anti-SpamBot Technology to your WordPress Registration and Comment Forms.
SpotBot aids in controlling spam before it clutters up your server. It stops bots in their tracks before they have a chance to post or force post.
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