title: Django app spam prevention
body: <p>we have a Django web application running on Ubuntu/Apache.  Lately, we've had a lot of issues with high volume spamming (comments, registrations, user contributed content, etc.).  </p>
  
  <p>We have <a href="https://docs.djangoproject.com/en/dev/ref/contrib/csrf/" rel="nofollow">CSRF</a> security in place, but am wondering what steps others have taken to curb this (ip table restrictions, Apache modules, captchas, etc)?   </p>