There's been a lot of talk about AT&T's crusade against rogue tethering lately, and it all comes back to this AT&T text message sent to some poor iPhone customer(s):
AT&T Free Msg: We’ve noticed you’re continuing to enjoy the tethering feature with your smartphone service. Remember, you need a tethering plan ($45/mo, incl. 4GB) to use this feature, so we’re planning to update your line with the required plan soon.
Yes, the carrier everyone loves to hate is cracking down on unauthorized tethering - and they are automatically switching violators onto AT&T's 4GB data plan with tethering access, at a steep $45 a month. There's just one little detail it seems some folks are forgetting to mention: there hasn't been a single reported case of this happening to an Android device on AT&T's network. Not one. But why?
Jailbroken iPhones typically use the same tethering technique as a standard iPhone, the one that's already present in iOS. This method exposes tethering activity quite readily, because the iPhone, when in tethering mode, sends traffic through an alternate APN (AT&T access point/router) for the express purpose of identifying the traffic as tethered data. This makes it extremely easy for AT&T to identify whether or not an iOS device is utilizing tethering, and just how much of their data is consumed via tethering.
Some tethering applications for iOS make use of alternative methods and route tethered traffic through the phone's normal data APN, but by and large, most jailbreakers stick with the stock application because it's easy to use and doesn't require any complicated setup. In fact, many iPhone users jailbreak for the sole purpose of avoiding AT&T's tethering fees (for why, see next section). These are the people AT&T's is going after.
Android tethering, on the other hand, isn't set up to route data through an alternate APN when the phone is in tethering mode - meaning AT&T would actually have to scan packets to determine whether or not you're tethering. This requires diversion of AT&T's resources (read: money), while identifying iPhone tethering is markedly simpler (read: cheap). AT&T's Android device population is also relatively small, while iPhone plans represents a very large chunk of AT&T's total revenue. But that's not the only reason AT&T is sticking it to iPhone users.
Unlimited Must Die
Many iPhone users have been grandfathered in under the special (and no longer offered) Unlimited iPhone Data plan offered by AT&T up until the launch of the iPhone 4 last year. Some are probably even on old Cingular unlimited data plans. AT&T really wants to get them onto tiered plans, because this gets AT&T more cash from subscriptions, and simultaneously reduces load on the network. Evil, but smart.
Jailbroken iPhones on these old plans can, then, tether to their hearts' contents with no worries about usage or bandwidth caps, or pesky overage fees. AT&T, understandably, doesn't like this. The way AT&T sees things, you're getting two services for the price of one - unlimited iPhone data, and an unlimited mobile broadband connection. This is a fair assertion. If you're getting unlimited access to AT&T's network, a laptop tethered to your iThing can chew through the megabytes like nobody's business, and do it far more quickly than you would on your phone's slim mobile browser or email app.
Now, I realize this logic only makes sense applied to unlimited data plans. If you're on AT&T with a 2GB DataPro plan, it seems to me that 2GB of data is two gigabytes of data however you slice it - why does AT&T care how you use it? The argument could be made that the amount of data uploaded or the amount of time with download speeds maxed could be greater when tethering on a laptop - but I still feel like this is a bit of a copout. Regardless, if you're doing a lot of tethering in the first place, it's unlikely you're staying under that 2GB mark (I average about 3.5GB/month).
Why Not Android?
Android users on AT&T, on the other hand, are much more rarely on older AT&T data plans - many have migrated from other carriers, or are first-time smartphone owners. This means they've been on AT&T's capped DataPro plans since day one, and any overages they incur are being charged at a rate of $10/GB. For those who consume less than 3GB of data a month and also use their device to tether, this does present a bit of a conundrum if AT&T ever decides to go after unauthorized Android tethering, maybe forcing someone from $25-$35 a month for data to $45 a month.
There really isn't a lot of incentive for AT&T to go after these people, though - as they aren't mitigating any data usage abuses (if anything, it might cause people to use more data), and they have to work harder to identify these people in the first place. Compare that to the incentives for going after the iPhone users with unlimited plans, and it doesn't make much fiscal sense.
Also, remember: $45 means you get 4GB to use however you want - tethered or not. Compare this to Verizon's tethering and data arrangement of $50 a month for unlimited mobile data and 2GB of tethered data, and it suddenly becomes less clear who the bigger rip-off is.
If there's one thing to take from all this, it's that if you're an Android user and an AT&T customer, you probably don't have to worry about getting auto-switched to the DataPro 4GB with Tethering plan any time soon. AT&T probably (perhaps in characteristic fashion) doesn't care enough about Android users to do anything about it at this point, and may never.
AT&T is attempting to stop the most egregious abusers of unauthorized tethering, and it seems unlikely that the company would want to devote the time and resources to something that probably wouldn't yield much in the way of results (read: money). When Android starts fighting Apple for domination of AT&T's subscriber base, then there may start being cause for concern. But until then, please: don't panic.