This is for site owners who want visitors to be able to post comments, but not have to register with the site to do so.
When a comment is posted, later visitors can vote "yes" or "no" on the comment (as in dailykos.com), or click "report" for inappropriate comments. The administrative area for this component lists reported comments and comments with more than three "no" votes. The administrator can delete reported comments, and also blacklist the IP address of the commenter.
This component uses Ajax, and the vote count is updated immediately.
This component, unfortunately, requires a patch to the K2 core. A patch file for version 2.5 of K2 is provided.
This component was updated in December, 2011 to work with Joomla 1.7 and K2 v2.5