Session session = new Session();
    session.Connect(...);
    StatisticsManager statisticsManager = StatisticsManager.GetInstance(session);
    AlertCatalog alertCatalog = new AlertCatalog(statisticsManager);
    AlertListener alertListener = new AlertListener(statisticsManager);

    AlertSet.Property[] properties = new[]
                                               {
                                                   AlertSet.Property.AccessMode,
                                                    AlertSet.Property.AlertDefinitions,
                                                    AlertSet.Property.Created,
                                                    AlertSet.Property.Description,
                                                    AlertSet.Property.DisplayString,
                                                    AlertSet.Property.Id,
                                                    AlertSet.Property.Modified,
                                                    AlertSet.Property.ModifiedBy,
                                                    AlertSet.Property.Owner,
                                                    AlertSet.Property.OwnerDisplayName,
                                                    AlertSet.Property.SubscribedByOther,
                                                    AlertSet.Property.SubscribedByUser,
                                                    AlertSet.Property.AlertSetSubscribers
                                                };

    alertCatalog.StartWatching(AlertSetCategories.All, properties);

    alertListener.AlertReceived += AlertListenerAlertReceived;
    alertListener.AlertChanged += AlertListenerAlertChanged;

    // This will return all AlertSets from the server when using <see cref="F:ININ.IceLib.Statistics.Alerts.AlertSetCategories.All" /> or <see cref="F:ININ.IceLib.Statistics.Alerts.AlertSetCategories.AdminAccess" />.
    var watchedAlertSets = alertCatalog.GetWatchedAlertSets();

    // Build AlertFilterKeys
    List<AlertFilterKey> filterKeys = new List<AlertFilterKey>();

    foreach (AlertSet alertSet in watchedAlertSets)
    {                                
        filterKeys.AddRange(BuildAlertFilterKey(alertSet));
    }

    // If AlertSetCategories.All or AlertSetCategories.AdminAccess was used this will start a watch on every unique AlertDefinition in each AlertSet.
    // **This is where performance could be impacted.**
    alertListener.StartWatching(
            filterKeys.ToArray(),
               AlertListenerFilter.Action | AlertListenerFilter.Condition | AlertListenerFilter.Severity);
}

private IEnumerable<AlertFilterKey> BuildAlertFilterKey(AlertSet alertSet)
{
    List<AlertFilterKey> alertFilterKeys = new List<AlertFilterKey>();
    List<string> uniqueTargets = new List<string>();

    foreach (AlertDefinition alertDefinition in alertSet.AlertDefinitions)
    {
        foreach (AlertRule alertRule in alertDefinition.AlertRules)
        {
            foreach (AlertAction alertAction in alertRule.AlertActions)
               {
                   if (!uniqueTargets.Contains(alertAction.TargetId))
                   {
                      uniqueTargets.Add(alertAction.TargetId);
                       alertFilterKeys.Add(new AlertFilterKey(alertSet, alertAction.TargetId));
                   }
               }
           }
    }

    return alertFilterKeys;
}