David Garcia

According to WordPress documentation, by default, clicking the .more-link anchor opens the web document and scrolls the page to section of the document containing the named anchor (#more-XXX). This section is where writers choose to place the  tag within a post type. With this plugin we can prevent this scroll down.
Visit the <a href="http://www.seocom.es/" rel="nofollow ugc">Seocom website</a> for more information.

Prevent Read More Scroll

Prevents the page scroll that occurs when clicking in the read more links.

sdesalas

This plugin allows WordPress to block over 95% of spam comments using a time-based hash.
This allows for a minimum sanity check and yet should remove almost all spam comments 
without the need to sign up to any third party APIs.
The plugin has been tested in real world conditions for around 12 months. It will not block 
real comments and it is pretty effective against spam, however it only uses a very simple 
algorithm and for that reason some spam comments may still make it through.

WP Simple SpamCheck

This plugin allows WordPress to block over 95% of spam comments using a time-based hash.

Prevent Read More Scroll vs WP Simple SpamCheck