In a curiously worded statement, AT&T has claimed it prevented the iPhone version of SlingPlayer from using 3G because it would chew too much data — and because the iPhone is, oddly, not considered a phone.

The short message justifies the decision to allow Sling Media’s remote streaming only without 3G use by first noting that a Slingbox consumes a large amount of bandwidth on AT&T’s cellular towers and could “prevent other customers from using the network.”

However, it’s here that the wireless provider’s argument takes an unusual turn. As mentioned by Engadget, AT&T specifically cites its terms of service — which have flip-flopped over the past several weeks — as preventing users from re-routing a TV signal through the 3G connection to a personal computer. But rather than add smartphones to the clause, the company tries to fit the iPhone into this category by claiming that it’s too powerful to be a regular smartphone.

“Applications like this, which redirect a TV signal to a personal computer, are specifically prohibited under our terms of service,” AT&T claims. “We consider smartphones like the iPhone to be personal computers in that they have the same hardware and software attributes as PCs.”

Instead, the carrier says, iPhone owners should be content to stream Slingbox video when away from home through the free Wi-Fi access they have at certain public locations, such as Starbucks coffee shops. Web video streams are also allowed.

This explains the lack of 3G with the iPhone version of SlingPlayer, but it sounds like AT&T just being afraid of their bandwidth being chewed up, and causing more issues with their service.