AT&T (NYSE: T) must be getting awfully nervous as its data-munching smartphone customers start heating up the virtual tar, and plucking feathers off their Farmville chickens. As fellow Fool Rick Munarriz noted earlier in the week, the wireless telecom giant is finally adding the long-desired tethering option starting June 7 -- but at the expense of its all-you-can-eat unlimited data buffet for new subscribers. Current users with plans will be grandfathered in ... unless they want to add tethering, that is.

You could almost hear the screams of the outraged millions erupting on blogs and Twitter feeds across the land, describing AT&T in ways that would make Genghis Khan and Attila the Hun seem like choirboys by comparison. You wouldn't, however, have heard me screaming yesterday, and you won't today, or even tomorrow. As an Apple (Nasdaq: AAPL) iPhone user, I'm also a AT&T subscriber ... and I have to say that I'm pretty much OK with the change.

Big ups to all my haters
Now, all the haters and doomsayers might be right to excoriate AT&T, but I'm just not seeing why. My average data consumption (and I'd consider myself a data-intensive iPhone user) bears out AT&T 's assertion that 98% of its users should be just fine with the standard 2-gigabyte limit:

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Of course, anecdotes aren't necessarily evidence, but I'm reasonably certain that I'm representative of the average user who accesses email, Internet apps, various social media outlets, and the occasional YouTube video with their smartphone. For the past six months, I've averaged around 35-36 megabytes of data via 3G, and the six months previous to that were about the same. This is modest to medium usage, I'd guess, because I use exponentially more than that via the Wi-Fi connection to my ISP at home, or through various AT&T hotspots -- free to AT&T subscribers on the new plans -- found in convenient and abundant places like Starbucks or even McDonald's. I expect that the same will hold true for the 3G iPad I just purchased.

Now, the torch-and-pitchfork crowd will argue that I'm sitting pretty in first class on the issue, because my iPhone data plan will be grandfathered in -- and they'd be right. But since I'm seriously considering the tethering option for those times where I'm not at home or at a hotspot, that would put me right back in steerage with the new subscribers. Looking at my data usage above, I'm still OK with that, because my most intensive usage -- like most average users, I contend -- will continue to be through my home Wi-Fi or the AT&T hotspots I'd only get as a subscriber, leaving me with plenty of room to surf away on the 3G seas.

Bring on the data deluge
Don't get me wrong: I don't necessarily agree with AT&T's decision to do this, but I get why the telecom's doing it. With a new iPhone likely rolling out of Cupertino this month, and more than 2 million iPads sold, AT&T is doing exactly what it should do to keep its data pipes unclogged. Tethering will likely place an additional strain on a network that already has a reputation for bursting its capacity seams. Now, if data-hoggers do exceed the standard 2-gigabyte limit, they'll pay more for additional gigabyte chunks on top of that, which will in turn help maintain and even upgrade the network to keep up with the demand for the average user. That's a win for AT&T shareholders, I'd think.

And if you believe that demand will diminish with subscribers jumping ship to Verizon (NYSE: VZ) or Sprint (NYSE: S), think again: Along with AT&T, these companies already had a quietly mentioned 5-gigabyte cap in place on "unlimited 3G" plans -- and you can be sure they'll be watching closely to see how much of a hit AT&T actually takes in subscriber churn from the data-plan changes.

But, hey, I could be wrong. If you think that's the case, by all means, let me know in the comments below. I'll be responding to them via my iPad and AT&T connection from the Starbucks around the corner.

Apple and Starbucks are Motley Fool Stock Advisor picks. Sprint got the nod from Motley Fool Inside Value. Try any of our Foolish newsletter services free for 30 days.

Fool online editor Tom Cadorette holds stock in Apple, Starbucks, and Verizon, but not in any of the other companies mentioned. He also owns several Apple products, and has a picture of Steve Jobs hanging in his bedroom. The Fool's disclosure policyonce called Tom a hipster, and told him to stop wearing black turtlenecks to the office all the time.