AT&T finally got with the times and offered iPhone users official tethering despite the fact that the iPhone and the capability for a long time. AT&T in its infant suck had blocked the feature out of fear of putting its already sketchy networking in many areas under even more pressure. It took the Verizon iPhone getting the tethering feature to finally get AT&T to man up.
Apparently, despite the fact that the tethering feature is now officially offered with the iPhone, many geeks are still using their jailbroken devices and third party apps to tether their iPhone and AT&T isn't happy about it. Reports claim that AT&T has started cracking down on users that have not adopted the official tethering plans and still tether with third party apps.
The carrier is sending SMS messaged to the users of jailbroken iPhones reminding them to sign up for tethering and pay more if they want to use the iPhone that way. AT&T is also sending out emails telling the customers that they will be automatically added to a tethering plan if they don’t sign up for one willingly.