danmz

Background/Motivation: Historically analytics and tracking have been used without explict user consent. 
Recently there has been a push to change this, both from a technical standpoint and from a legal standpoint. 
While analytics are recognized to be useful to website owners, users should be aware that they are being tracked, and have the option to avoid this tracking.
This plugin aims to make it easy and simple to get tracking/analytics consent from users, and respect the users’ stated preferences for the most common tracking scenarios. 
The user’s preferences are stored for the duration of their browser session.
This plugin removes known tracking scripts (google, facebook, and crazyegg) from generated markup until a user explicitly opts in to allow their use. 
This applies to all markup prior to <code>wp_footer();</code>. Due to limitations of WordPress hooks we cannot filter content after this. 
This plugin attempts to ONLY block markup whose stated purpose is tracking (such as items from the googletagmanager.com domain), and not other items which might potentially do tracking.
This plugin also clears known tracking cookies associated with those known trackers for users who have not opted in to tracking functionality.

Check Permission Dialogue

This plugin adds an opt-in permission for certain known tracking scripts and tracking cookies.

Automattic

Donncha O Caoimh (a11n)

This plugin adds a stylesheet or image to your blog’s html source code. When a browser loads that stylesheet or image a cookie is dropped. If that user then leaves a comment the cookie is checked. If it doesn’t exist the comment is marked as spam. 
The plugin can also check how long it took a user to enter a comment. If it’s too fast it’s probably a spam bot. How fast can a legitimate user enter their name, email, web address and enter a well thought out comment?
For the adventurous, add these lines to your .htaccess and it will block spam attempts before they ever get to WordPress. Replace the Xs with the cookie that was set in your browser after viewing your blog. You can also find the cookie value by examining the page source code and looking for “css.php?k=XXXXXXXXXXXXXXXXXXX”. Make sure the lines go above the standard WordPress rules.
<pre><code> RewriteCond %{HTTP_COOKIE} !^.*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.*$
 RewriteRule ^wp-comments-post.php - [F,L]
</code></pre>
If you use WordPress MU, replace wp-comments-post.php above with wp-signup.php to block spam signups.
<pre><code> RewriteCond %{HTTP_COOKIE} !^.*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.*$
 RewriteRule ^wp-signup.php - [F,L]
</code></pre>

Cookies for Comments

If you don't use any other spam filter plugins, then you can rely on this to stop spam comments for sure!

Must have, if you don't use any other spam filters!

I'd been getting a dozen spams a day on two of my sites. We installed "Stop Spam Comments" on one and "Cookies for Comments" on the other. Both worked perfectly. No more spam. Thanks!



very easy and no more spam!

Sets 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.

Check Permission Dialogue vs Cookies for Comments