When you create a product and business model that shape-shifts the entire cellular industry—your fate is tied to partners who may not share the same vision, values, or aspirations (no need for sympathy—the only thing worse, of course, is to watch it all happen from the sidelines).  A not-so-brief chat with Randall Stephenson of AT&T in the "Secret Diary of Steve Jobs" captured the experience perfectly.

The problem, according to AT&T, is that hardcore iPhone users—the customers AT&T shares with Apple—are using the "smart" in smartphones too much:

The carrier has had trouble keeping up with wireless data usage, leading to dropped connections and long waits for users trying to run
programs on their devices. AT&T is upgrading its network to cope,
but its head of consumer services, Ralph de la Vega, told investors at
a UBS conference in New York that it will also give high-bandwidth
users incentives to "reduce or modify their usage." (see story).

As fake Steve Jobs explains to AT&T's CEO:

And now here we are. Right here in your own backyard, an American
company creates a brilliant phone, and that company hands it to you,
and gives you an exclusive deal to carry it — and all you guys can do
is complain about how much people want to use it.