AT&T is informing jailbreak tetherers on grandfathered unlimited data plans that either they stop tether or sign up for 2GB tethering plan. If you don’t abide, AT&T will sign you up for a 2GB tethering plan and kill your grandfathered unlimited data plan for good.
A thorny wicket. It’s probably not fair to congest AT&T’s networks by sucking up data from your iPhone to play World of Warcraft on your MacBook Pro without, you know, paying for it, but if you’re intent on doing so, there may be a way to avoid AT&T’s scrutiny, keep tethering through your jailbroken iPhonei, and keep your unlimited data plan, all at the same time.