Putting in my old SIM card did nothing to bypass the activation screen. It just shows you have cell signal. I even got a new sim card from Simply Mac and it did nothing.
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UPDATE:
I restored the phone with iOS8... didn't help.
Here are my scenarios:
1. Wifi connection = Get 'ATT was unable to verify your identity' error.
2. iTunes connection = Get 'ATT was unable to verify your identity' error.
3. Cellular connection = Get 'It may take a few minutes to activate your iPhone', and then says 'ATT activation server can not be reached'.
Simply put, Apple blames it on ATT's activation servers. They said that one server went up in 'smoke' yesterday it was that overloaded. ATT tells me everything on their end is already activated for me, and that its a phone issue that apple must resolve. I tell Apple this, and the only thing left to do is get a new phone. But when I have a 6+, it'll be WEEKS before thats possible.
TERRIBLE EXPERIENCE.