title: Select items from List A where the property is not in List B
body: <p>I have a <code>List&lt;Broadcast&gt;</code> and the <code>Broadcast</code> object has a property called <code>Guid</code>. Now I need to find all <code>Broadcast</code> objects in that list whose <code>Guid</code> property is not an item in <code>List&lt;Guid&gt;</code>.
  I've found a solution with <code>Except();</code> but it's not working for me.</p>
  
  <pre><code>Broadcasts.Where(x =&gt; x.Guid).Except(readBroadcasts);
  </code></pre>
  
  <p>What am I doing wrong?</p>