Fresno, California --
If you're someone who has a hard time putting down your iphone ... your wallet may soon feel the effect. AT&T announced Wednesday ... it's working on a tiered pricing plan ... for iphone users who use a heavy amount of data.The phone carrier says just 3% of smartphone users consume 40% of network capacity ... slowing down internet access for millions of other cell phone users. Right now, AT&T does not limit subscribers from how much data they can use. But officials say they'll soon charge customers based on how much web access they use.