The Federal Communications Commission has sent letters to T-Mobile, AT&T, and Comcast asking for information on programs that allow their customers to stream music, videos, or other content without having it count toward their data cap. The inquiry is a big deal. Net neutrality advocates argue that these programs violate the commission's rules, giving a distinct competitive advantage to the apps and services that they let customers use data free; upstarts, they argue, will always fail in comparison. The FCC avoided directly addressing this issue when it established its new net neutrality rules earlier this year, but today's inquiry suggests that it shares some of these competitive concerns.

"We want to ensure that we have all the facts."

"We want to ensure that we have all the facts to understand how these services relate to the commission's goal of maintaining a free and open internet while incentivizing innovation and investment from all sources," the FCC writes in each letter. It's asked the three companies to make staff available to them for discussions within a month.

The three internet providers argue that their services do not violate net neutrality. T-Mobile, which offers data-free music and video streaming for select services, tells The Hill that its program "encourages competition, and we believe it is absolutely in line with net neutrality rules." Comcast, which offers its own data-free streaming TV service, argues in a statement to the Los Angeles Times that it's offering a "cable service" not subject to net neutrality rules, as opposed to a streaming service that goes "over the public internet." AT&T, which lets companies pay to offer data-free services, tries (and fails) to sound super punk, saying, "We remain committed to innovation without permission and hope the FCC is too."

FCC chairman Tom Wheeler emphasizes that these letters do not constitute the beginning of a formal investigation. "Let me be real clear," he said at an event today, according to The Hill. "This is not an investigation, this is not an enforcement. This is to help us stay informed as to what the practices are as we said we would do."

But presumably, if the FCC doesn't like what it sees, it could turn into a deeper look at this business practice and a formal decision on in what — if any — circumstances it's allowed. FCC commissioner Ajit Pai, who has opposed the net neutrality rules, suspects that's exactly what's happening here. "This is not simply a benign information inquiry," he said, according to The Hill. "The agency is obviously trying to gather facts to determine whether or not those services comport with the net neutrality regulations the majority adopted this last February."