Paying for an unlimited data plan doesn’t mean you get unlimited access to your carrier’s bandwidth. AT&T, T-Mobile and Verizon Wireless slow down, or throttle, data users after they reach a predetermined limit. Sprint is the lone hold-out, but rumors point to the possibility that the carrier will begin to throttle data on its Virgin sub-carrier plans. The justification for this process involves regulate network traffic and minimize bandwidth congestion. And with the rise in 4G data usage, carriers claim their networks are jammed. But for consumers, this means you may not get to take advantage of all the speed promised by a new 4G smartphone.