Firefox 28.0 Mac OS 10.9.2 I keep getting small pop-up notices from Firefox (Firefox emblem in the pop-up), telling me that "Joe Smith [insert name of one of my Facebook friends there] has Unfriended you." It only stays on the screen for a few seconds and disappears. Oddly, none of these people have actually unfriended me in Facebook. Facebook does not send Unfriend notices. I know there is an app for Firefox that does this, but I cannot find any trace of it in my Firefox Applications list and I do not recall installing it. Nothing with "Facebook" or "Unfriend" in my Firefox app list. (Someone else in the household may have installed it, but they are not talking. ;) I searched my hard drive for "unfriend" and "Unfriend" and found nothing. At this point, it is an annoyance, but it bothers me that something like this could become malicious. Any help would be greatly appreciated. Thanks for your time.