Are iPhone users are ruining cell-phone reception for the rest of us? As smartphones become more popular, the problem could spread from AT&T, which carries the iPhone exclusively, to other networks. The New York Times reports that Apple's phone users guzzle network capacity at about 10 times the rate of the average smartphone user, because owners download applications, stream media, and browse the web at higher rates than most other users. AT&T is sinking $18 billion into network upgrades and expansions to relieve demand, but in the meantime overuse is resulting in dropped calls, delayed message delivery, plodding download speeds, and annoyed customers—particularly during peak hours in urban areas. Regular cell phone users shouldn't gloat yet either—as smartphones become more popular, the data bottleneck could get worse across multiple networks.