title: Block by useragent or empty referer
body: <p>A stranger bot (GbPlugin) is codifying the urls of the images and causing error 404.<br>
  I tried to block the bot without success with this in the bottom of my .htaccess, but it didn't work.</p>
  
  <pre><code>Options +FollowSymlinks  
  RewriteEngine On  
  RewriteBase /  
  RewriteEngine on  
  RewriteCond %{HTTP_REFERER} !^$  
  RewriteCond %{HTTP_USER_AGENT} ^$ [OR]  
  RewriteCond %{HTTP_USER_AGENT} ^GbPlugin [NC]  
  RewriteRule .* - [F,L]     
  </code></pre>
  
  <p>The log this below.  </p>
  
  <pre><code>201.26.16.9 - - [10/Sep/2011:00:06:05 -0300] "GET /wp%2Dcontent/themes/my_theme%2Dpremium/scripts/timthumb.php%3Fsrc%3Dhttp%3A%2F%2Fwww.example.com%2Fwp%2Dcontent%2Fuploads%2F2011%2F08%2Fmy_image_name.jpg%26w%3D100%26h%3D65%26zc%3D1%26q%3D100 HTTP/1.1" 404 1047 "-" "GbPlugin"
  </code></pre>
  
  <p>Sorry for my language mistakes</p>