AT&T customers surprised by data speed limits

AT&T has some 17 million customers with "unlimited data" plans that can be subject to throttling, representing just under half of its smartphone users.

It stopped signing up new customers for those plans in 2010, and warned last year that it would start slowing speeds for people who consume the most data. What's surprising AT&T’s customers is how little data use it takes to reach that level — sometimes less than AT&T gives people on its "limited" plans. Users report that if they call the company to ask or complain about the throttling, AT&T customer support representatives suggest they switch to the limited plan.

AT&T spokesman Mark Siegel said that as of last summer, the top 5 percent of data users were using 2 gigabytes of data per month. But he also said the company doesn't actually throttle all of the top 5 percent "unlimited" data users. Last month, the figure was only 0.5 percent, or about 200,000 people, he said. That's because AT&T only throttles users in areas where the wireless network is congested that month, Siegel said. Siegel also pointed out that aside from moving to a tiered plan, "unlimited" plan users on the cusp of being throttled can use one of AT&T's 30,000 Wi-Fi hotspots, where usage is unmetered.