diff -u b/src/Plugin/monitoring/SensorPlugin/UserIntegritySensorPlugin.php b/src/Plugin/monitoring/SensorPlugin/UserIntegritySensorPlugin.php
--- b/src/Plugin/monitoring/SensorPlugin/UserIntegritySensorPlugin.php
+++ b/src/Plugin/monitoring/SensorPlugin/UserIntegritySensorPlugin.php
@@ -34,6 +34,13 @@
   protected $configurableValueType = FALSE;
 
   /**
+   * The max number of users to list in the verbose output.
+   *
+   * @var int
+   */
+  protected $list_size =500;
+
+  /**
    * {@inheritdoc}
    */
   public function runSensor(SensorResultInterface $sensor_result) {
@@ -114,22 +121,22 @@
       return [];
     }
 
+    $query = \Drupal::entityQuery('user')
+      ->sort('access', 'DESC')
+      ->range(0, $this->list_size);
+
     // The authenticated role is not persisted and it could have restrict access
     // so we load every user.
     if (in_array('authenticated', $role_ids)) {
-
-      // The conditions apply to all users.
-      $users = User::loadMultiple();
-
-      // We don't need the default user with uid = 0.
-      unset($users[0]);
-      return $users;
+      $uids = $query->condition('uid', '0', '<>')
+        ->execute();
+    }
+    else {
+      // Load all users with the roles.
+      $uids = $query->condition('roles', $role_ids, 'IN')
+        ->execute();
     }
 
-    // Load all users with the roles.
-    $uids = \Drupal::entityQuery('user')
-      ->condition('roles', $role_ids, 'IN')
-      ->execute();
     return User::loadMultiple($uids);
   }
 
@@ -211,6 +218,7 @@
       $processed_users[$id]['mail'] = $user->getEmail();
       $processed_users[$id]['password'] = hash('sha256', $user->getPassword());
       $processed_users[$id]['changed'] = $user->getChangedTime();
+      $processed_users[$id]['last_accessed'] = ($user->getLastAccessedTime() != 0) ? $user->getLastAccessedTime() : null;
     }
     return $processed_users;
   }
@@ -234,6 +242,7 @@
     // Create rows for new users.
     foreach ($new_users_id as $id) {
       $time_stamp = $current_users[$id]['changed'];
+      $last_accessed = $current_users[$id]['last_accessed'];
       $user_name = array(
         '#theme' => 'username',
         '#account' => User::load($id),
@@ -244,6 +253,7 @@
       $row['expected_value'] = ['#markup' => ''];
 
       $row['time'] = ['#markup' => date("Y-m-d H:i:s", $time_stamp)];
+      $row['last_accessed'] = ['#markup' => isset($last_accessed) ? date("Y-m-d H:i:s", $last_accessed) : 0];
       $rows[] = $row;
     }
 
@@ -254,6 +264,7 @@
       $changes = $this->getUserChanges($current_users[$id], $expected_users[$id]);
       foreach ($changes as $key => $value) {
         $time_stamp = $current_users[$id]['changed'];
+        $last_accessed = $current_users[$id]['last_accessed'];
         $user_name = array(
           '#theme' => 'username',
           '#account' => User::load($id),
@@ -264,10 +275,17 @@
         $row['expected_value'] = ['#markup' => $value['expected_value']];
 
         $row['time'] = ['#markup' => date("Y-m-d H:i:s", $time_stamp)];
+        $row['last_accessed'] = ['#markup' => date("Y-m-d H:i:s", $last_accessed)];
         $rows[] = $row;
       }
     }
 
+    // Show query.
+    $output['message'] = array(
+      '#type' => 'item',
+      '#title' => t('Table shows new and changed users who have privileged access.'),
+    );
+
     if (count($rows) > 0) {
       $header = [];
       $header['user'] = t('User');
@@ -275,12 +293,19 @@
       $header['current_value'] = t('Current value');
       $header['expected_value'] = t('Expected value');
       $header['time'] = t('Changed on');
+      $header['last_accessed'] = t('Last accessed');
 
       $output['users'] = array(
         '#type' => 'table',
         '#header' => $header,
       ) + $rows;
     }
+    else {
+      $output['result'] = [
+        '#type' => 'item',
+        '#markup' => t('No matching users were found.'),
+      ];
+    }
     return $output;
   }
 
diff -u b/src/Tests/MonitoringCoreWebTest.php b/src/Tests/MonitoringCoreWebTest.php
--- b/src/Tests/MonitoringCoreWebTest.php
+++ b/src/Tests/MonitoringCoreWebTest.php
@@ -205,12 +205,11 @@
 
     // Create an authenticated user and test that the sensor counter increments.
     $test_user_third = $this->drupalCreateUser(array(), 'test_user_3');
-    $this->drupalLogin($test_user_third);
     \Drupal::keyValue('monitoring.users')->deleteAll();
     $result = $this->runSensor('user_integrity');
     $this->assertEqual($result->getMessage(), '4 privileged user(s), Anonymous user has privileged access, Authenticated user has privileged access, Self registration possible.');
 
-    $test_user_third->setUsername('changed');
+    $test_user_third->setUsername('changed2');
     $test_user_third->save();
 
     // Check sensor message for user changes.