News:
The permissions of the code which invoked the Demand method will be evaluated.
For permissions which do a stack walk, an exception will occur only if NONE of the calling codes has the required permission
For permissions which do a stack walk, an exception will occur if ANY of the calling codes does not have the required permission
The permission levels of individual stack frames are always checked regardless of the permission type.
When a stack walk is performed, Demand succeeds only if no SecurityException is raised. Useful resources, IPermission.Demand method