AT&T Mobility routinely trumpets the number of iPhones it activates each quarter, as well as the data revenues generated by those iPhone sales. However, the carrier has been less forthcoming about the strains all of that data traffic is putting on its network. In an interview with the New York Times, AT&T's chief technology officer conceded the difficulties in keeping pace with iPhone users' data demands. "It's been a challenging year for us," said CTO John Donovan. "Overnight we're seeing a radical shift in how people are using their phones. There's just no parallel for the demand." Article