Improvements are provided for hubs for wall mounting systems for screens, and in particular to a hub for a wall mounting system for a flat panel screen, such as a plasma display or television screen, which enables the screen to be tilted. In particular, the disclosure relates to the synchronization of related requests for processing of data using distributed network resources. The interaction analyzer identifies from the description an action that causes a deviation from a progression of presentation of the content that would have occurred had the action not taken place.