p.s. this is why anyone with half a clue disables any and all browser plugins.
Wishful thinking.
The common setting you see in browsers is an all-or-nothing deal, which constrains you to visiting text only sites until you open the menu to open a preferences menu to change the setting (that affects all plugins rather than just untrusted ones.)
It took Google Chrome several attempts to get it right. First, they added plugin blocking in some menu. Then they added a button in the address bar that allows unblocking plugins. Then, the bug where that button unblocked plugins for multiple tabs/windows was fixed. Finally, they added a right-click menu to unblock individual plugins (which helped, since that first button only allowed one click).
Firefox support for blocking plugins is miles behind a non-updated version of Opera. In Opera, there's actually a menu item that disables plugins, and it's not too deep either. While the latest version doesn't allow unblocking individual plugins, it's still easy to unblock if necessary.
Oh, and if an extension implements what should be core browser functionality, then maybe it should be added to the browser instead of forcing extension authors to do the work.