AT&T has finally decided to allow tethering on the iPhone. Of course, they're charging an arm and a leg for it, and dragging their feet on actually launching the feature. It's pretty clear that AT&T is not happy about the idea of tethering. But why have they fought against it so fiercely while other mobile carriers let it go on without charging a dime?

To be honest, the fault lies with the iPhone owners themselves. They browse the Internet 40x as often as other smartphone owners. That means extra expenses for AT&T, especially since so many iPhone users have unlimited data plans.

If AT&T were to allow free tethering, their users would surf them out of house and home. Information may want to be free, but that doesn't mean accessing it is.