This plugin will send a 404 header for every public page on your blog.
Do you have a blog that really only want ready by humans? Do think that robots should never be able to read your blog, even if they ignore your robots.txt? Is privacy your number one concern? Do your friends think of you as "that total privacy nut...you know too much so."? Then this plugin is for you. The 404er will make every public page of your blog return a 404 instead of the normal 200. Yes, you could use the normal privacy subpanel, but that would be sooo pedestrian. Step up to the real (excessive, RFC abbusing) 404!
Note: If you did not detect any humor in the above text or you do not know what a 404 is, then, in all caps, DO NOT INSTALL THIS PLUGIN!