As we noted last week, AT&T and Apple's decision to block the Google Voice application from the iPhone application store is a very clear instance of anti-competitive behavior protecting SMS and long distance revenues. In response, the FCC has issued a set of three letters (1, 2, 3) to the companies asking how exactly the Google Voice application came to be banned after it was submitted some six weeks ago. AT&T has directed all questions from the press on the matter to Apple, who has yet to comment publicly on the scuff up. The questions posed include:

•What role, if any, did AT&T play in Apple’s consideration of the Google Voice and related applications?

•Did Apple act alone, or in consultation with AT&T, in deciding to reject the Google Voice application and related applications?

•Please explain any differences between the Google Voice iPhone application and any Voice over Internet Protocol (VoIP) applications that Apple has approved for the iPhone.

•What other applications have been rejected for use on the iPhone and for what reasons?

Many wonder if the FCC has enough authority to do more than publicly place a little shame on both AT&T and Apple, but that may be all that's required. The response from the companies will most certainly be that certain applications are hindered or banned if they pose a threat to the network. That was the case earlier this year when the Apple and AT&T restricted 3G functionality on both the Skype and Slingbox iPhone applications.

However, while sometimes legitimate, network congestion claims have become sort of a "get out of jail free" card for anti-competitive behavior. Since carriers share no raw data on network performance, they're in effect able to claim that anything adversely impacts network performance without having to provide proof. As for AT&T, they're sticking to their position that they had nothing to do with it.

"AT&T does not manage or approve applications for the App Store,” the company said in a statement. "We have received the letter and will, of course, respond to it."