Forcing an unwanted window to quit

I consider this a "security" improvement feature.
Currently, the Ubuntu OS incorporates the tool called "Force Quit" (e.g. Force a misbehaving application to quit).

Note:
You can find this if you:
1. Right-click on the Top Panel,
2. Select "Add to Panel...",
3. Under "Desktop & Windows" select "Force Quit",
4. Click on the button named "add" & then on button named "close".
5. The button named "Force Quit" is added on your Top Panel & you are ready to use it.

Let me suggest that another button, named "Force Close" should be introduced for Security purposes.
The difference between the buttons "Force Quit" & "Force Close" is that the former closes an open application, but the later closes an open window (and not the whole application!).

Let me provide the reasoning why we need this, with a "User Case" [u]Example[/u]:

User Dimitris launches his Mozilla Firefox browser to surf on the Internet. The user visits an Internet site/page, where a pop up window appears (Note: sometimes pop windows appear, even though users have [u]specifically[/u] instructed the Browser not to allow pop up windows).
User Dimitris is not interested for the contents/links provided by the pop up window, and decides he wants to close the pop up window. Unfortunately, his Ubuntu OS does not show a Title Bar with the available "minimize/maximize/close" buttons, for the user to close the window properly.
Instead there is a "close" button embedded in the popup window. User dimitris is puzzled... He knows that by clicking the embedded button named "close", there is a chance that he
(unwillingly) initiates installation of malicious code (e.g. spyware, etc etc) in his Ubuntu OS.
Based on the fact that user dimitris does not know what code might be initiated from his clicking on the embedded pop up window's button named "close", he prefers instead to use Ubuntu's embedded feature "Force Close" (e.g. Force an unwanted window to close).

This feature is different from the current embedded Ubuntu feature "Force Quit" (e.g. Force a misbehaving application to quit), because the "Force Quit" feature closes the whole Mozilla Application - i.e. every Mozilla Firefox's open window.
And the user needs to re-open each & every window again...
(Note: when the user re-opens the above windows, after applying "Force Quit", the pop up does not pop up again.)
Instead, the "Force Close" would close only the pop up window & leave the Mozilla Firefox's remaining windows open.

[u]Summary[/u]:
By implementing/using the "Force Close" button, a user is able to close a single window of Mozilla Firefox & leave the remaining Firefox's open windows intact.
I consider this a very important feature, especially for security purposes!

Thanks.