As if things couldn't get worse for AT&T, there are reports coming out from customers who are trying to upgrade to the new iPhone 4 via AT&T's website that they are being directed to different accounts, owned by strangers.

This comes after a weekend-long fraud update on AT&T's website (and just after the massive iPad 3G email leak), but instead of protecting customers' sensitive info, when customers log in to their accounts, they see phone numbers, billing addresses, phone call lists, and other sensitive info that does not belong to them. Apparently, this breach occurs when someone tries to upgrade to an iPhone 4, but you don't necessarily have to be upgrading for someone to see your private information.

This totally explains why customers were unable to preorder a new iPhone 4 and why AT&T stores were having such a hard time processing preorders in store this morning. So far, there have been reports of all kinds of errors, mistakes, and overcharging of accounts if you've preordered through AT&T's upgrade portal, which has since been disabled.