This isn’t something AT&T can force, afaik. Two things: 1. Go to Settings > WiFi and turn Ask to Join Networks ON. 2. Any time you are auto-connected to a ne

This isn’t something AT&T can force, afaik. Two things: 1. Go to Settings > WiFi and turn Ask to Join Networks ON. 2. Any time you are auto-connected to a network and don’t want to do that again, go to Settings > WiFi, tap the blue info icon next to the currently active wifi network, and then tap Forget this Network when the details show up. Ask to Join Networks is usually off by default. That means your phone will always attempt to join any public wifi without asking you first. Apple thinks this is friendlier for people. All known networks, once joined, will forever be auto rejoined in the future unless you turn Ask ON and forget each network you connect to (except those you trust and want to auto-join).