You dont need to think about what user has
bookmarked. Bookmarking doesnt mean that it allows access to user at anytime.Its your application who decides whether to allow acces to this request or not [based on some conditions].
The security you are talking about can be easily achieved using e.g. Forms Authentication. A very basic example can be found here.
How to: Implement Simple Forms Authentication[msdn][
^]
After applying this concept, Any unauthenticated user will be redirected to Login page. This will give you more accuracy while working with the security.
[EDIT]:
ASP.NET Session State shared between IE Tabs and IE8[
^].
asp.net - session - multiple browser tabs - different sessions?[
^]
I think this is the thing what you needed.
Regards.. :laugh: