How to make the Twitter title field a hidden field?

Ok, I found the code below where I can make this change (I think), but I don't know how to start. All I want is that a node author DOES NOT have the option to change the $form['twitter']['status']['#default_value'] = variable_get('twitter_default_format', 'New post: !title !tinyurl'); line. My best option would be to make that a hidden field, is that possible? So the only option the user would have is the checkbox to post to Twitter or not.

module_load_include('inc', 'twitter');

    $twitter_form = twitter_form();
    if (!$twitter_form) {
      return;
    }
    $form['twitter'] = array(
      '#type' => 'fieldset',
      '#title' => t('Post to twitter.com'),
      '#collapsible' => TRUE,
      '#collapsed' => FALSE,
      '#tree' => TRUE,
    );
    $form['twitter']['post'] = array(
      '#type' => 'checkbox',
      '#title' => t('Announce this post on Twitter'),
      '#default_value' => (empty($form['nid']['#value'])),
      '#id' => 'twitter-toggle',
    );
    $form['twitter'] += $twitter_form;
    $form['twitter']['status']['#default_value'] = variable_get('twitter_default_format', 'New post: !title !tinyurl');
    $form['twitter']['status']['#description'] = t('