title: Weird characters in URL
body: <p>In my webserver when user requests URLs with weird characters, I remove these characters. And system logs these cases. When I check sanitized cases I found these. I'm curious that what would be the objective of these URLs ?</p>
  
  <p>I check the IPs and these are real people and uses website as a normal person. But 1 time in their 20 URL requets of these people, URL has these weird characters at last.</p>
  
  <pre><code>http://example.com/@%EF%BF%BD%EF%BF%BD%02?o=3&amp;g=&amp;s=&amp;z=%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%3E?, agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0,
  http://example.com/%60E%EF%BF%BD%02?o=3&amp;g=&amp;s=&amp;z=%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%3E?, agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0
  http://example.com/%60E%EF%BF%BD%02?o=3&amp;g=&amp;s=&amp;z=%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%3E?, agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0
  http://example.com/p%EF%BF%BD%1D%01?o=3&amp;g=&amp;s=&amp;z=%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%3E?, agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0
  http://example.com/%EF%BF%BDC%EF%BF%BD%02?o=3&amp;g=&amp;s=&amp;z=%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%3E?, agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0
  http://example.com/%EF%BF%BDR%EF%BF%BD%02?o=3&amp;g=&amp;s=&amp;z=%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD%EF%BF%BD`%EF%BF%BD%EF%BF%BD%7F, agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36
  http://example.com/%EF%BF%BDe%EF%BF%BDv8%01%EF%BF%BD?o=3&amp;g=P%01%EF%BF%BD&amp;s=&amp;z=%EF%BF%BD%EF%BF%BD%15%01%EF%BF%BD%EF%BF%BD, agent: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.114 Safari/537.36
  </code></pre>
  
  <p><a href="http://en.wikipedia.org/wiki/Specials_(Unicode_block)">http://en.wikipedia.org/wiki/Specials_(Unicode_block)</a></p>