[TEC] Hide certain events from site guests

/**
 * Filters the list of events. Any events belonging to $eventCategory
 * will be removed if the user is not logged in.
 *
 * @param array $events
 * @return array
 */
function protect_marked_events($events) {
    // If the user is logged in we need take no further action
    if (is_user_logged_in()) return $events;

    // The category name or slug we wish to protect
    $eventCategory = 'heavy-metal';

    // Filter out any events that belong to the above category
    foreach ($events as $id => $event)
        if (has_term($eventCategory, TribeEvents::TAXONOMY, $event->ID))
            unset($events[$id]);

    // Return our modified list of events
    return $events;
}

add_filter('tribe_get_events', 'protect_marked_events');