anchor.diff:  
   Consider a chat application.
   
  -* User's can send messages to a specific user by sending a message to the destination of "/app/chat".
  +* Users can send messages to a specific user by sending a message to the destination of "/app/chat".
   * The application sees the message, ensures that the "from" attribute is specified as the current user (we cannot trust the client).
   * The application then sends the message to the recipient using `SimpMessageSendingOperations.convertAndSendToUser("toUser", "/queue/messages", message)`.
   * The message gets turned into the destination of "/queue/user/messages-<sessionid>"
  
positive.code:         </b:bean>
      </b:constructor-arg>
  </b:bean>
  ----
negative.code: 
  This will ensure that:
  
  <1> Any message without a destination (i.e. anything other than Message type of MESSAGE or SUBSCRIBE) will require the user to be authenticated
  <2> Anyone can subscribe to /user/queue/errors
  <3> Any message that has a destination starting with "/app/" will be require the user to have the role ROLE_USER
  <4> Any message that starts with "/user/" or "/topic/friends/" that is of type SUBSCRIBE will require ROLE_USER
  