One would think AT&T would be the carrier to look at when you consider the network that's known to transfer the most amount of data across their network; especially with data hungry iPhone owners eating up their fair share. Interestingly enough, AT&T wasn't the actual leader in that category, but both Verizon and Sprint managed to stay on top of the number two wireless carrier all of last year. Most of the blame can be attributed to AT&T's network issues that hindered them from being placed higher on the list for carrying the most data traffic in 2009. According to ABI Research, both Sprint and Verizon topped AT&T – Big Red took the number one spot with Sprint coming in at second; when combined, the two carriers generated 63 percent of the US market's mobile network data traffic. In reality, it's not the myriad of smartphones that cause the most amount of data to be transferred. Instead, Verizon's and Sprint's laptop mobile data connections far exceeded the numbers put up by AT&T – strangely enough, lower data-consuming business customers consisted a good majority of Sprint's and Verizon's laptop connections. Looking at projected trends, Verizon is expected to keep its spot at number one over the course of the next five years while AT&T's traffic will increase steadily and eventually take the runner up position by 2012. T-Mobile unfortunately takes the fourth spot followed by a bunch of other mobile operators – obviously being late to the 3G game can have a drastic affect on these numbers.