Even if your lawyer is somehow able to pull a Harry's Law and convince a court to rule that way, the end result is guaranteed to be that no US wireless carrier will ever offer an unlimited smartphone data plan again.
Big win.
Firstly - I am no lawyer, and will not pretend to be.
Absolutely agree with this (above). AT&T or any other carrier are not required by law to sell you something. "Management reserve the right to sell".
I am also confused by folks stating that "unlimited means unlimited". How are you going to enforce this? By sighting the same contract you think can be ripped up? You can't pick and choose the paragraphs to suit your viewpoint/case.
The outcome will be simple...AT&T will hold their hands up - they got it wrong, and when contracts end, they will refuse to renew them (goodbye GF plans).
Sure - if you manage to win this class action before your contract ends, then you may get a little unlimited tethering for a while, but even if signing today...2 years? No chance. It will take years. Very short sighted, me thinks.