T-Mobile will allow customers to stream unlimited amounts of video from select partners without having those streams count against their data limits starting this Sunday, CEO John Legere said today. At launch, the service will include 24 different partners, including Netflix, Hulu, HBO Now, and SlingTV. (YouTube was conspicuously absent.)

The company also said it will double the data limits for all of its plans and will offer its customers 30 percent off Sling TV service.

That’s great news for Netflix junkies on the go, or for low-income customers on a budget. But with new federal regulations in place to ensure a more open Internet, T-Mobile’s new offering could also face greater scrutiny.

The new service, dubbed Binge On, complements T-Mobile’s existing Music Freedom service, which exempts many major music streaming apps, including Spotify and Apple Music, from customers’ data limits. Both services are examples of what’s known as “zero rating,” that is, singling out specific apps and services from counting toward data limits.

Music Freedom program is one of the most well-known zero-rated offerings, but it’s not the only one. Facebook’s controversial Internet.org program subsidizes access to Facebook and other sites in developing countries. Last year Sprint launched a prepaid wireless service that included the option of getting unlimited data for certain sites, such as Facebook or Pinterest, but not others. And AT&T has flirted with the idea of sponsored apps that wouldn’t count towards your bandwidth limit.

The idea of zero-rating would seem to stand in stark contrast to the principle of net neutrality, where all services are treated equally, whether they’re music streaming services, file sharing applications, or any other type of service—and whether they’re operated by well-funded startups or by rag-tag community non-profits.

But legally, zero-rating falls into a gray area within the FCC’s open internet rules passed earlier this year. “The record in the Open Internet proceeding reflected both benefits from/concerns about zero-rating, so we didn’t ban such plans but will look at them case-by-case and act as necessary,” says FCC spokesperson Mark Wigfield.

Wigfield didn’t comment specifically on T-Mobile, but T-Mobile’s new video streaming offering would seem to be one of those cases.

Legere dismissed these concerns. “This is not a network neutrality problem,” he said. T-Mobile defends its zero rating services by saying that it doesn’t charge streaming companies to participate in Music Freedom or Binge On, and it will allow any legal streaming service to join the program—including porn sites—so long as they meet the technical standards. In other words, there’s no paid prioritization and no discrimination, in theory, between different music or video streaming services.

In practice, however, Music Freedom only included seven services at launch. It has now expanded to 33 different services, but one of the biggest worries is that T-Mobile’s services will keep small services from growing by making it even harder for them to attract new customers, and that new services will also be hobbled by the need to strike deals with T-Mobile and other carriers to get their services zero rated. For example, Internet radio company SomaFM has complained in the past about not being included in Music Freedom. Founder Rusy Hodge says the company is finally set to be included, but it’s taken months as well as a number of technical changes to make it happen. It looks like SomaFM’s struggle will have a happy ending, but the company may have missed opportunities to attract new listeners, and its experience shows how difficult the program can be for smaller operations without extensive technical teams or the name recognitition to accelerate the appication process.

The video streaming service also raises new questions about zero-rating. Offering unlimited video streaming seems to undermine the idea that data caps are necessary in the first place. If video and music streaming can be done for free, why not chat services like Skype? Why not online gaming? Why not photo sharing or file storage services like Dropbox? Why not just offer unlimited data? However open T-Mobile claims its plans are, clearly some favorites have already been picked.