Consumer advocacy group Public Knowledge has asked regulators to stop Comcast from exempting its own streaming video service from Internet data caps, saying that selective enforcement of caps violates a merger condition from when Comcast purchased NBCUniversal and may violate a net neutrality rule.

Public Knowledge filed its petition with the Federal Communications Commission yesterday. It relates to "Stream TV," a service for Comcast's Internet-only customers that streams live TV channels to computers, tablets, and phones. Stream TV doesn't require a set-top box, but Comcast says it "is an in-home cable service delivered over Comcast's cable system, not over the Internet." Stream TV offers some video outside the home, but live TV channels can only be watched on Comcast customers' home Internet connections.

Public Knowledge points out that when Comcast won government approval to buy NBCUniversal in 2011, the FCC and Department of Justice "prohibited Comcast from excluding its own services from data caps or metering and required it to count traffic from competing online video services the same as its own." Public Knowledge also says the data cap exemption for Stream TV should be stopped by the FCC's net neutrality order; though the net neutrality rules don't specifically ban zero-rating, the FCC imposed a "general conduct" rule to be applied on a case-by-case basis. That rule is meant to stop practices that limit consumers' access to content or the ability of online service providers to reach consumers.

Comcast argues that Stream TV's data cap exemption doesn't violate the merger condition or net neutrality because it is a cable service and not an Internet one. Public Knowledge is trying to convince the FCC that Comcast is wrong.

The merger condition's exact phrasing was that Comcast "shall not measure, count, or otherwise treat Defendant’s affiliated network traffic differently from unaffiliated network traffic."

"Stream TV is 'network traffic' for the purpose of this [merger] restriction, no different than traffic from video services like Youtube and Netflix," Public Knowledge's petition said. "Customers access Stream TV via their broadband Internet access subscriptions. It is not available on a standalone basis without a broadband connection, as MVPD [multichannel video programming distributor] services such as cable TV are. Stream TV data travels over the same path as other broadband data, from Comcast’s network, and through the cable modem in customers’ homes. Additionally, viewers watch Stream TV on the same devices (such as personal computers and mobile devices) they use to watch other online video services."

Public Knowledge further argued that "Comcast appears to believe that it need do nothing more than physically locate the servers which offer a given broadband service on its own property for that service to be categorically immune from various consumer protection policies."

Comcast: “Public Knowledge doesn't have the facts straight”

Comcast, which has instituted 300GB monthly data caps and overage charges in parts of its territory, won't be backing down. The company provided Ars a statement, saying that "Public Knowledge doesn’t have the facts straight."

"Our Stream TV cable package does not go over the Internet, so it can’t possibly violate a condition which only applies to Internet content... Stream TV is delivered as a cable service on the same private, managed network that delivers all our other cable television services in the home and is subject to all the regulations that apply to our other cable TV services such as franchise fees, PEG requirements, closed-captioning, and emergency alerts. Those regulations don’t apply to content that goes over the Internet, just another demonstration how different Stream TV is than Internet delivered services."

Comcast also said the FCC declined to take any action on a similar complaint Public Knowledge filed a few years ago about Comcast zero-rating an Xbox streaming application.

FCC staff will review Public Knowledge's petition and decide how to proceed, but an FCC spokesperson declined to comment on the merits of the petition. The consumer group asked the FCC to require that Comcast either "eliminate its data caps to the extent they discourage the consumption of online video" or count Stream TV against data caps and take any enforcement action necessary to deter future, similar arrangements.

The Comcast/NBCUniversal merger conditions had a time limit and expire in 2018. The net neutrality rules that apply to the whole broadband industry are permanent (unless they're overturned in court), but it's not clear how strong a stance the FCC is ready to take against zero-rating. The FCC is examining zero-rating implementations from Comcast, AT&T, and T-Mobile, but it hasn't said whether it will put a stop to any of them.

The FCC's net neutrality order only vaguely outlines circumstances in which zero-rating or other practices might violate its so-called "general conduct rule." ISP practices that give end users control over how they access the Internet "and empower meaningful consumer choice" are not likely to violate the rule, the order says. Practices that have anti-comeptitive effects or discourage innovation or investment in online services would be more likely to be deemed violations.

Public Knowledge argues that these factors should weigh heavily against Comcast.

"By employing data caps and selectively zero-rating its own services, Comcast is reducing the likelihood that increased subscriber demand for unaffiliated online services will drive broadband investment," the group wrote. "It is harming innovation in the edge services market, since Stream TV is not competing through the quality of the overall offering or through a novel business model, but through employing billing practices that are not available to unaffiliated services."

A Comcast FAQ indicates that Stream TV may soon be available to people without Comcast Internet service. "If you're not an Xfinity Internet customer, we are working hard to make the required equipment available in 2016," Comcast says. But it would still only be available inside Comcast's cable footprint, because the company wouldn't have programming rights to sell the service elsewhere, a company spokesperson told Ars.