by: Mark Kurlyandchik

AT&T Mobility has been hit with yet another class action lawsuit, the Courthouse News Service reports. The lawsuit alleges that AT&T overstates the amount of data used by iPhone and iPad customers each month, and also charges for phantom data.
The class says AT&T's billing system "is like a rigged gas tank that charges for a full gallon when it pumps only nine-tenths of a gallon into your car's tank."
Named plaintiff Patrick Hendricks claims that an independent consulting firm that was hired by his counsel discovered these charge. During a two-month study, the firm "found that AT&T systematically overstate web server traffic by 7 percent to 14 percent, and in some instances by over 300 percent. So, for example, if an iPhone user downloads a 50 KB website, AT&T's bill would typically overstated the traffic as 53.5 KB (a 7 percent overcharge) to as high as 150 KB (a 300 percent overcharge)."
On top of this overstatement of data consumption, Hendricks also claims that AT&T charged for data that was never transferred. The same consulting firm purchased an iPhone from an AT&T store and immediately disabled all push notifications, location services, e-mail accounts, etc. Then, they let the device sit untouched for 10 days. "During this 10-day period, AT&T billed the test account for 35 data transactions totaling 2,292 KB of usage. This is like the rigged gas pump charging you when you never even pulled your car into the station," the lawsuit claims.
And while the class claims that these charges have only "a modest effect" on individual customers' bills, "they have a huge effect on AT&T's bottom line." With more than 92 million customers, AT&T could potentially be falsely inflating its revenues if these charges are legitimate.
AT&T is no stranger to class action lawsuits. According to Courthouse News, previous cases have been brought against the carrier claiming it charged for downloads customers never made, charged for services it didn't (or couldn't) deliver, and promised that iPhones could send SMS and MMS, among others.