title: State of the art in spam prevention
body: <p>What is the current state of the art in Spam Prevention techniques? </p>
  
  <p>I've already read Paul Graham's articles about Bayesian filtering. (<a href="http://www.paulgraham.com/spam.html" rel="nofollow">A Plan for Spam </a> and <a href="http://www.paulgraham.com/better.html" rel="nofollow">Better Bayesian Filtering</a>)</p>
  
  <p>and wanted to know if there is some more up to date articles available?
  (preferably AI related ones)</p>