If you still have an "unlimited" data plan with AT&T and you're among the top 5% of data users, prepare to be throttled.
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.
AT&T stresses they're [not the only one doing this](http://www.imore.com/ta, and that most users will never see the throttling, just those heaviest, most video streaming, sneakily tethering, packet clogging, network reputation ruining five-percenters.