AT&T obviously isn't relying on either honor or guilt to get people to stop unofficially tethering their phones. Having sent out SMS warnings last month to smartphone users caught tethering without a special data plan that they were flouting the carrier's policies, AT&T has apparently followed up with a second message, reports TiPB, saying they'll be automatically upgrading users to the appropriate package, an extra
$45 $25 per month.
"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. Visit att.com/dataplans or call 888-860-6789."
Many iPhone owners had used unofficial WiFi hotspot apps like MyWi to share the handset's connection out with their tablets, notebooks and other devices. While AT&T offers this functionality officially, it also charges extra for it: the regular smartphone data plan only covers on-device browsing and messaging.
What will be interesting is how AT&T reacts to the inevitable complaints from subscribers demanding they prove they have been tethering. Automatically subscribing people to a new, expensive add-on is likely to provoke no small amount of vitriol.
Update: AT&T has pointed out that the actual extra fee is $25 per month - on top of the existing $20 on-device data plan. That gets you an extra 2GB of data for use on any device for a total of 4GB.