title: How effective is the honeypot technique against spam?
body: <p>By "honeypot", I mean more or less this practice:</p>
  
  <pre><code>#Register form
  &lt;style&gt;
      .hideme{
          display:none;
          visibility: hidden;
      }
  &lt;/style&gt;
  &lt;form action="register.php"&gt;
      Your email: &lt;input type="text" name="u-email" /&gt;
      Choose a password: &lt;input type="text" name="passwd" /&gt;
      &lt;div class="hideme"&gt;
          Please, leave this field blank: &lt;input type="text" name="email" /&gt;  #the comment is for text-browser users
      &lt;/div&gt;
      &lt;input type="submit" value="Register" autocomplete=off /&gt;
  &lt;/form&gt;
  
  //register.php
  &lt;?php
  if($_POST['email'] != ''){
      die("You spammer!");
  }
  //otherwise, do the form validation and go on.
  ?&gt;
  </code></pre>
  
  <p>more info <a href="http://nedbatchelder.com/text/stopbots.html" rel="noreferrer">here</a>.</p>
  
  <p>Obviously, the real fields are named with random hashes, and the honeypot fields can have different names (email, user, website, homepage, etc..) that a spambot usually fills in.</p>
  
  <p><strong>I love this technique because it doesn't cause the user to be annoyed by CAPTCHA.</strong></p>
  
  <p>Do any of you have some experience with this technique? Is it effective?</p>