AT&T has begun sending messages to iPhone and possibly Android users it believes are tethering without paying for a matching plan. The notices tell subscribers that their service "may need updating" with the 4GB DataPro tethering plan since it believed they were using tethering but were still on one of the device-only plans. Subscribers were told to either stop tethering or else face being automatically signed up for the $45 tethering plan on the next billing period, which at least for OSXDaily was March 27.
