This question applies to both my iPhone and my Macbook, so I am posting in the general section. I am trying to find a way to prevent my devices from automatically joining networks I have previously been connected to. The reasons do not really matter here, but one is security (I may have been connected to some network that I do not actually trust and have forgotten to "forget" the network), another one is that that at work we have two networks, and every day my iPhone joins the wrong one so I have to go to the settings and change it back (I sometimes need to use the other network so I can't "forget" it). In an ideal world, the "ask to join networks" option would do exactly this (both in Mac OS and iOS), but known networks will be joined irrespective of the setting. This is really driving me nuts, and it's impossible to find a solution with Google or the forum search because there are millions of threads about Macs _not_ joining networks they are supposed to. My iPhone is jailbroken and I am not afraid of command line hacks. If there is any solution to this, I would be very grateful.