This seems to be a firefox pref that the shumway devs are using during their automation tests. You can find it being used in many places across mozilla source

This seems to be a firefox pref that the shumway devs are using during their automation tests. You can find it being used in many places across mozilla source code. https://github.com/search?q=org%3Amozilla+turn_off_all_security_so_that_viruses_can_take_over_this_computer&type=Code https://github.com/search?q=org%3Amozilla+turn_off_all_secur... You can also find a number of tickets asking for it to be removed, this one is 6 years old :D https://bugzilla.mozilla.org/show_bug.cgi?id=984012 https://bugzilla.mozilla.org/show_bug.cgi?id=984012