Oh come on, are you really "surprised" by a limit on your unlimited data plan? If you are really surprised, why not return the favor and "surprise" AT&T with a class action suit?
What's surprising people like Trang is how little data use it takes to reach that level — sometimes less that AT&T gives people on its "limited" plans. Trang's iPhone was throttled just two weeks into his billing cycle, after he'd consumed 2.3 gigabytes of data. He pays $30 per month for "unlimited" data. Meanwhile, Dallas-based AT&T now sells a limited, or "tiered," plan that provides 3 gigabytes of data for the same price.