Both made the most of a report showing 1% of smartphones used 25% of the available bandwidth, and that each subsequent generation of iPhones used more data than the one before.
Both pointed the finger at users for inconsiderate bandwidth hogging, even though most of the really excessive bandwidth use came not from users but from Siri--the talking, overly cute digital assistant that's the one big feature Apple keeps promoting about the iPhone (and which, all by itself on the iPhone 4S, uses three times the bandwidth of the entire iPhone 4).
Any network manager realizes that if 1% of users take up 25% of the bandwidth, something has to be done to those users right away.
Verizon and AT&T switched to data caps and fee hierarchies to make those data-hogging users pay for the temerity to buy a phone the carriers promoted so heavily, and then to actually use the phone and its major features for the purposes for which they were designed.
They also claimed they had to increase fees and tighten other restrictions so they could afford to upgrade their networks to keep up with iPhone users--which is a big pipe full of hooey.
AT&T, for one thing, told existing users they could keep the unlimited data plan unless they abused the privilege by using too much data. Then it started changing the criteria for what it meant by "too much," without making too obvious an effort to warn users.
Verizon, at least, never promised it would keep the unlimited data plan, and kept that lack of promise.
In fact, Verizon announced well ahead of time it wouldn't grandfather iPhone users upgrading to iPhone 5 into unlimited data plans. Upgrade your iPhone and you're back on pay-by-the-drink, it said.
That annoyed people so much Verizon had to agree (a day later) to allow the existing unlimited accounts, though it said the price would be that iPhone users with the unlimited plans would get none of the hardware subsidies that make buying a phone bearable. IPhone 5 users would have to pay full price.
You might think the duplicitous history of unlimited data plans would put end users off, but it isn't so. AT&T has already announced it set a sales record with the iPhone 5 last weekend and bragged a bit about its plan to let them use Facetime and talk time simultaneously, to contrast with Verizon's already-reversed plan to let users videoconference or use the phone, but not both at the same time. (Verizon stuck to the decision to make iPhone 5 users pay full price for the hardware, though.)
In both cases, the most likely reason is the extra competition from MetroPCS, T-Mobile, Sprint and other carriers who can suddenly burden their networks with the iPhone just as Verizon and AT&T complained.
Next: Why Are Carriers Bugging IT With All This Juvenile Nonsense