Today on the server logs I found about 2900 404 errors triggered from a single IP, the logs are similar as
[IP REMOVED] keralaonline.com - [27/Apr/2009:11:38:34 +0530] "GET /wp-content/uploads/2009/04/photo993.jpg HTTP/1.0" 404 18013 "https://keralaonline.com/wp-content/uploads/2009/04/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
[IP REMOVED] keralaonline.com - [27/Apr/2009:11:38:38 +0530] "GET /wp-content/uploads/2009/04/photo997.jpg HTTP/1.0" 404 18013 "https://keralaonline.com/wp-content/uploads/2009/04/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
[IP REMOVED] keralaonline.com - [27/Apr/2009:11:38:39 +0530] "GET /wp-content/uploads/2009/04/photo999.jpg HTTP/1.0" 404 18013 "https://keralaonline.com/wp-content/uploads/2009/04/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
one can see that the request is scripted and at a random interval, seems to be a script kiddie trying to leech images, but I got worried that even for this wordpress would go and output my pretty 404 page, which was as you could see is a whopping 17Kb, and takes about half a second to build. So just gave a twist and modified the top area of my 404 template to
<?php
if(eregi('/wp-content',$_SERVER['REQUEST_URI'])){
echo '<h1>Not found</h1>';
exit();
}else
get_header(); ?>
which changed the traffic down to 18 bytes per 404 error, as in
[IP REMOVED] keralaonline.com - [27/Apr/2009:22:15:10 +0530] "GET /wp-content/themes/Kol/jiju.jpg HTTP/1.1" 404 18 "-" "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.5) Gecko/2008121621 Ubuntu/8.04 (hardy) Firefox/3.0.5; https://www.jijutm.com"