Listening to Events in the calendar from more than one person using EWS API
===

Simply I would like to receive a notification every time someone added a new appointment or made any changes on what he/she has. 

The only way I know how to do it , is by using 
service.SubscribeToStreamingNotifications
but the problem here that it only listens to the account that the service is bound to like in this way

    var service = new ExchangeService(ExchangeVersion.Exchange2010_SP2)
                                      {Credentials = new WebCredentials(userName, password)};

     service.SubscribeToStreamingNotifications(new FolderId[] { WellKnownFolderName.Calendar },
                                                            EventType.FreeBusyChanged,EventType.Deleted);

 I have solved this problem by creating a list of services each service is bounded to different user and the application should listen to each of them. 
 
The problem with this way is that I need to have the password of each account I wont to listen to its events, which is not possible in real world. 

so is there any way to deal with that ? 

