diff --git a/blocks/online_users/block_online_users.php b/blocks/online_users/block_online_users.php
index e44468cae6a..2fd93d477a9 100644
--- a/blocks/online_users/block_online_users.php
+++ b/blocks/online_users/block_online_users.php
@@ -88,14 +88,23 @@ class block_online_users extends block_base {
 
         $this->content->text = '<div class="info">'.$usercount.' ('.$periodminutes.')</div>';
 
-        // Verify if we can see the list of users, if not just print number of users
-        if (!has_capability('block/online_users:viewlist', $this->page->context)) {
+        // Verify if we can see the list of users, if not just print number of users.
+        // If the current user is not logged in OR it's a guest then don't show any users.
+        if (!has_capability('block/online_users:viewlist', $this->page->context)
+                || isguestuser() || !isloggedin()) {
             return $this->content;
         }
 
         $userlimit = 50; // We'll just take the most recent 50 maximum.
+        $initialcount = 0;
         if ($users = $onlineusers->get_users($userlimit)) {
+            require_once($CFG->dirroot . '/user/lib.php');
+            $initialcount = count($users);
             foreach ($users as $user) {
+                if (!user_can_view_profile($user)) {
+                    unset($users[$user->id]);
+                    continue;
+                }
                 $users[$user->id]->fullname = fullname($user);
             }
         } else {
@@ -153,6 +162,14 @@ class block_online_users extends block_base {
                 }
                 $this->content->text .= "</li>\n";
             }
+            if ($initialcount - count($users) > 0) {
+                $this->content->text .= '<li class="listentry"><div class="otherusers">';
+                $this->content->text .= html_writer::span(
+                    get_string('otherusers', 'block_online_users', $initialcount - count($users))
+                );
+                $this->content->text .= "</div>";
+                $this->content->text .= "</li>\n";
+            }
             $this->content->text .= '</ul><div class="clearer"><!-- --></div>';
         }
 
diff --git a/blocks/online_users/classes/fetcher.php b/blocks/online_users/classes/fetcher.php
index a18e625caaf..a63e0ec73dc 100644
--- a/blocks/online_users/classes/fetcher.php
+++ b/blocks/online_users/classes/fetcher.php
@@ -86,7 +86,7 @@ class fetcher {
         }
         $params = array();
 
-        $userfields = \user_picture::fields('u', array('username'));
+        $userfields = \user_picture::fields('u', array('username', 'deleted'));
 
         // Add this to the SQL to show only group users.
         if ($currentgroup !== null) {
diff --git a/blocks/online_users/db/access.php b/blocks/online_users/db/access.php
index f238b7384d7..6e8b95b7429 100644
--- a/blocks/online_users/db/access.php
+++ b/blocks/online_users/db/access.php
@@ -55,7 +55,7 @@ $capabilities = array(
         'contextlevel' => CONTEXT_BLOCK,
         'archetypes' => array(
             'user' => CAP_ALLOW,
-            'guest' => CAP_ALLOW,
+            'guest' => CAP_PREVENT,
             'student' => CAP_ALLOW,
             'teacher' => CAP_ALLOW,
             'editingteacher' => CAP_ALLOW,
diff --git a/blocks/online_users/lang/en/block_online_users.php b/blocks/online_users/lang/en/block_online_users.php
index f34f5d68583..bf9cf6cfab6 100644
--- a/blocks/online_users/lang/en/block_online_users.php
+++ b/blocks/online_users/lang/en/block_online_users.php
@@ -23,6 +23,7 @@
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+$string['otherusers'] = 'Other Users ({$a})';
 $string['onlinestatushiding_desc'] = 'If enabled, users have the option to hide their online status from other users.';
 $string['configtimetosee'] = 'Number of minutes determining the period of inactivity after which a user is no longer considered to be online.';
 $string['onlinestatushiding'] = 'Online status hiding';
diff --git a/blocks/online_users/styles.css b/blocks/online_users/styles.css
index bebee5abc1b..8c895082a4d 100644
--- a/blocks/online_users/styles.css
+++ b/blocks/online_users/styles.css
@@ -7,6 +7,10 @@
     position: relative;
 }
 
+.block_online_users .content .list li.listentry .otherusers {
+    margin-left: 1.5rem;
+}
+
 .block_online_users .content .list li.listentry .user .userpicture {
     vertical-align: text-bottom;
 }
diff --git a/blocks/online_users/version.php b/blocks/online_users/version.php
index 1d951b56564..c86963d41d8 100644
--- a/blocks/online_users/version.php
+++ b/blocks/online_users/version.php
@@ -24,6 +24,6 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2021052500;        // The current plugin version (Date: YYYYMMDDXX)
+$plugin->version   = 2021052501;        // The current plugin version (Date: YYYYMMDDXX)
 $plugin->requires  = 2021052500;        // Requires this Moodle version
 $plugin->component = 'block_online_users'; // Full name of the plugin (used for diagnostics)