title: How do I do a "NOT IN" query in Mongo?
body: <p>This is my document:</p>
  
  <pre><code>{ 
      title:"Happy thanksgiving",
      body: "come over for dinner",
      blocked:[
         {user:333, name:'john'},
         {user:994, name:'jessica'},
         {user:11, name: 'matt'},
      ]
  }
  </code></pre>
  
  <p>What is the query to find all documents that do not have user 11 in "blocked"?</p>