If a hacker brings up an unsecured wifi access point named att-wifi, your AT&T iPhone will connect to it right now, without any notification or acknowledgment. Your phone will connect to att-wifi in your pocket or purse when you walk into a Starbucks. Your email and web surfing will be visible. All your network traffic can be sniffed, any clear passwords can be stolen.
Most access points require your approval to connect to them, but not att-wifi. Your AT&T iPhone will connect to att-wifi out of the box.
To disable this:
Walk into a Starbucks.
On your iPhone go to Settings -> Wi-Fi
Click the blue ball next to att-wifi.
Click “Forget this Network”
This “feature” was probably put here by Apple at the request of AT&T.
Apple, please disable this. It is a security risk to every AT&T iPhone user.