Comment 6 for bug 852961

Yes, I have confirmed that the unwanted notifications come from nm-applet. Removing nm-applet from startup applications works around the problem, but it is not a good workaround because Unity and Gnome Classic's panel don't start nm-applet on their own; they're stuck with whatever is set in gnome-session-properties, because everyone uses the same gnome-session. (It's also problematic because gnome-session-properties has been tweaked so removing a startup application specified by the system is difficult).