title: Request.AnonymousID in ApiController
body: <p>I'm using MVC 4 Web API and the Anonymous Identification Module to identify anonymous users for a shopping cart in my application. This is the value I've added to my web.config file:</p>
  
  <pre><code>&lt;anonymousIdentification enabled="true" /&gt;
  </code></pre>
  
  <p>I can access <code>Request.AnonymousID</code> in a normal <code>Controller</code> but not an <code>ApiController</code>. How can I access this?</p>