Ars Technica has confirmed that AT&T will begin throttling the data speeds of its heaviest wireless users beginning October 1.
AT&T spokesperson Jackie Vettorino told Ars that data throttling for heavy users will begin on October 1, and will only apply to users who still pay for unlimited data (and not users who pay for the non-unlimited tiers). The company has also posted a statement about the change on its website:
"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. This change will never impact the vast majority of our customers, and is designed to create a better service experience for all."
Verizon implemented a similar policy in February of this year.
Source: Ars Technica