When I get you right, You're talking about those scripts which are proposed to disable viewing Page source? When adding such a feature, one could also think about a function which disables pop-up windows when user closes a window/leaves a website. Opera 6 has a very nice implementation, which lets the user change such settings very quickly by pressing F12.
dup of bug 86193
Looks so. *** This bug has been marked as a duplicate of 86193 ***
marking verified as a duplicate. if you decide to reopen this bug, please clarify why. search string for bugspam removal: SalviaGuaranitica
Pref to disable alerts -> bug 185384