In 2011 AT&T warned its heavy data using mobile customers that it would reduce their connection speed if said usage inched in to the "top five percent." AT&T is defining that metric as anyone who uses more that 2.1 GB of data a month. As chronicled in this NYT blog post, one of AT&T's customers hit the 2.1 GB mark and had his connection throttled. The problem, that customer says, is that he has a data limit of 3GB a month because a legacy unlimited plan.
In 2010 AT&T discontinued its unlimited data plans, but customers who were already enrolled in the plan had the option to be grandfathered in and not affected by the changes.
John Cozen, the AT&T customer we just wrote about, was among the first to report receiving a throttle notice. Basically AT&T told him that his connection would be slowed down until the next billing cycle. Cozen says that it was unfair to be throttled because he pays $30 for an unlimited plan and has a 3 GB data cap.
In a phone interview AT&T spokesperson Mark Siegel told the New York Times that the "top 5 percent" of its heaviest data users have typically used 2 gigabytes of data or more a month. He also claims that their throttling policy does not target everyone that exceeds that number and that it is done on a case-by-case basis. I'm sure that provides solace to customers like John Cozen...
“There’s a very good chance you wouldn’t be slowed,” Mr. Siegel said. He went on to say that less than 1 percent of AT&T smartphone customers were affected by the policy last month.
Of course, AT&T’s throttling policy only applies to customers with unlimited data plans.