Detects comment SPAM and deletes it automatically.
Detects a link in the body of the comment and warns the commenter that their comment will be destroyed on sight. At this point a real legitimate commenter can make a decision to not include a link in their comment. An automatic spam bot will not care about that message and will just submit the message anyway. This is when the destruction begins, the plugin filters the message and obliterates it if it detects a link.