Ways to detect CTRL-N or when a user opens a new window

Question

How can we detect when a user opens a new window. The user is already authenticated and we make heavy use of sessions.

We were trying to avoid Ctrl+

Answer 1

What I have done to solve this issue is when the user authenticates set the window name on valid login.

And then on the master page do a javascript check:

If the check is true then hide/remove the main content of the page and show a message stating they are doing something unsupported.

This works when your login page is not tied into the master page.

If you do not have a master page then I would suggest putting the check on all your pages.