the insertion of a Master Page inside each Hybrid Module is not necessary. You can add a
Master Page (with the information about the logged user) to the Site View and it will be
visible to all the elements inside the Site View (Pages, Areas,...).
For the visualization of the content of the Master Page, the descendant order is considered.
In particular, a Master Page is searched inside the parent element; in case of absence it is searched inside the upper element and so on.
For example if there is an Area containing an Hybrid Module (whose implementation includes a Master Page), when you visit the pages inside the Area, the Master Page inside the Hybrid Module will be shown.
If the Area doesn't include an Hybrid Module with a Master Page, when you visit the pages
inside the Area, the Master Page inside the Site View will be shown (if the Site View have a Master Page).