ex_user.module

/**
 * Implements hook_block_view_alter().
 */
function ex_user_block_view_alter(&$data, $block) {
  // Allow the block to be hidden using a conf variable.
  if ($block->delta == 'masquerade' && !variable_get('ex_user_show_masquerade_block', 1)) {
    $data = array();
  }

  // Change the masquerade block title to reflect the masquerading state.
  if ($block->delta == 'masquerade' && isset($_SESSION['masquerading'])) {
    $data['subject'] = t('Masquerading');
  }