NEW YORK (AP) — Mike Trang likes to use his iPhone 4 as a GPS device, helping him get around in his job. Now and then, his younger cousins get ahold of it, and play some YouTube videos and games.

But in the past few weeks, there has been none of that, because AT&T Inc. put a virtual wheel clamp on his phone. Web pages wouldn't load and maps wouldn't render. Forget about YouTube videos — Trang's data speeds were reduced to dial-up levels.

"It basically makes my phone useless," said Trang, an Orange County, Calif. property manager.

The reason: AT&T considers Trang to be among the top 5 percent of the heaviest cellular data users in his area. Under a new policy, AT&T has started cutting their data speeds as part of an attempt to manage data usage on its network.

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