AT&T said yesterday that it will allow any customer with an LTE-capable iOS device on a tiered or shared data plan to use Apple's FaceTime video conferencing app over a cellular connection.

AT&T had previously said it would only allow users who switched to the company's new shared data plans to access the app on its wireless network, and other customers’ FaceTime use was limited to Wi-Fi.

The move comes as advocacy groups, including Free Press and Public Knowledge, threatened to file a complaint with the FCC over AT&T's Facetime policy. The groups argued that by excluding some customers from using the app, AT&T was in violation of net neutrality laws.

Jim Cicconi, AT&T senior executive vice president of external and legislative affairs, acknowledged "concerns" over the policy in a blog post on the company's website, saying that the initial decision to limit the app was due to concerns over the sheer number of iPhones on AT&T's network.

"AT&T has by far more iPhones on our network than any other carrier," Cicconi wrote, adding that when Apple rolls out new changes, as it did with iOS 6, "it can have a much greater, and more immediate, impact on AT&T’s network than is the case with carriers who have far fewer iPhone users."

Cicconi said that with the FaceTime app already preloaded on tens of millions of iPhones, there was no way for AT&T's engineers to model usage and assess network impact.

"It is for this reason that we took a more cautious approach toward the app," he wrote. "To do otherwise might have risked an adverse impact on the services our customers expect – voice quality in particular – if usage of FaceTime exceeded expectations."

Cicconi went on to explain that AT&T will support FaceTime not only on its Mobile Share plans, but also on all of AT&T’s tiered data plans with an LTE-capable iOS device.  The company expects to roll out this functionality over the next eight to10 weeks. 

In addition, AT&T is informing deaf and hard of hearing customers that on Oct. 26 it began rolling out several new billing plans designed to allow them to make use of FaceTime.

Advocacy groups like have been closely watching AT&T's handling of FaceTime,  arguing that while customer protections in place today for wireless players are too weak, they are still strong enough to block carriers from doing exactly what AT&T was doing with its FaceTime policy.

California congressional democrat Rep. Anna Eshoo, the ranking member of the Subcommittee on Communications and Technology, today released a statement supporting AT&T’s move to open use of FaceTime.

“I applaud AT&T’s announcement to commit to open service beyond its Mobile Share plan,” Eshoo said. “This is a victory for consumers and for those who know a free and open Internet is vital to sustaining our rapidly expanding mobile technology market.”

Since Apple opened up the use of FaceTime over a cellular connection in its latest iteration of iOS, AT&T was the only major carrier to put forth a FaceTime policy that excluded certain users. Verizon Wireless and Sprint both have policies that allow any device compatible with iOS 6, on any data plan, to use FaceTime on their wireless networks.