By MacRumors AT&T has quietly updated one of its policies to reflect that it will now only throttle customers that are connected to a cell tower experiencing network congestion, reports Ars Technica. The carrier previously throttled all grandfathered customers with unlimited data plans that exceeded 5GB of 4G LTE data usage in a single monthly billing period, regardless of network congestion.
The updated policy reads as follows:
Quote:

“As a result of AT&T’s network management process, customers on a 3G or 4G smartphone or on a 4G LTE smartphone with an unlimited data plan who have exceeded 3 gigabytes (3G/4G) or 5 gigabytes (4G LTE) of data in a billing period may experience reduced speeds when using data services at times and in areas that are experiencing network congestion. All such customers can still use unlimited data without incurring overage charges, and their speeds will be restored with the start of the next billing cycle.”

Last October, the U.S. Federal Trade Commission filed a federal court complaint against AT&T, accusing the carrier of misleading its smartphone customers by charging them for unlimited data while reducing their data speeds by up to 90 percent. The FTC claimed that AT&T did not adequately inform its customers that they would be throttled for using more than a certain amount of data during a billing cycle. AT&T could still face penalties from the FTC if it loses the case, despite changing its policy.
AT&T customers with unlimited data plans have experienced speeds as low as half a megabit per second when being throttled, according to the report, resulting in barely usable service. By throttling unlimited data plans, AT&T is naturally encouraging customers to switch to one of the tiered data plans that it introduced in the years after discontinuing unlimited plans. Verizon, Sprint and T-Mobile have similar throttling practices where there is network congestion.
Article Link: AT&T Scales Back Throttling of Grandfathered Unlimited Data Plans

Source: MacRumours