Yup, this sucks. AT&T has started throttling top 5 percent of data users on unlimited data plan, as they had planned. AT&T said that this was going to take effect starting on October 1st but as September 29 many customers are claiming that AT&T is already throttling their data usage by reducing the speed.
Starting October 1, smartphone customers with unlimited data plans may experience reduced speeds once their usage in a billing cycle reaches the level that puts them among the top 5 percent of heaviest data users. These customers can still use unlimited data and their speeds will be restored with the start of the next billing cycle. Before you are affected, we will provide multiple notices, including a grace period.
Verizon also started to throttle customers on 3G unlimited data plan a few weeks back calling it ‘Network Optimization’ by reducing the speed to its top 5 percent data users as well.