Comment 25 for bug 481541

(From update of attachment 160985)
Ugh yes, Firefox does load middle-click tabs in the background by default. I
forgot that Firefox and Sunbird for some reason override the default
application setting. So the Grandmother Argument is back.

Nevertheless, this patch won't fly, either. It removes from the UI the ability
to control middle-click tab focus. We can't change functionality at this point.
Agreed, we need to reconsider the UI after the UI freeze. And that my example
of timer window.open was extreme.

This morning I think the solution is to leave the control of left-click tab
focus in the hands of the loadInBackground pref as it currently stands, but
allow Jim's new loadDivertedInBackground pref to override that setting if it
exists. That seems to me to afford the least surprise to a mid-level user
reading the text of the Options dialog, while giving a power user the ability
to fine-tune, and extensions a hook for a more complete UI.