• by Wendy Davis , Staff Writer @wendyndavis, January 29, 2016

T-Mobile's new "Binge On" service "undermines the core vision of net neutrality," Stanford professor Barbara van Schewick says in a new report about the service.

"The program harms competition, user choice, free expression, and innovation," the professor says in a 51-page paper published Friday.

Binge On, introduced in November, exempts video streams offered by Netflix, Amazon and more than three dozen other providers from consumers' data caps. T-Mobile says that any video providers can join Binge On for free, if they meet the company's technical requirements.

But the service is controversial for several reasons. One is that Binge On automatically throttles video streams offered by all companies -- not just the participants -- to 1.5 Mbps, which is too slow for HD video. The result is that some users experience choppy streams unless they explicitly opt out of Binge On.

The service also riles net neutrality advocates because its technical requirements exclude some video distributors -- including YouTube, Periscope, educational sites like Coursera and a host of small companies. Schewick's report largely focuses on those exclusions. She argues that T-Mobile shouldn't give people incentives to watch videos from some companies and not others.

"A core principle of net neutrality is that ISPs should not pick winners and losers online by favoring some applications over others," she writes. "But that’s exactly what Binge On does."

Schewick also argues that the program harms free expression because it zero-rates sites offering professional entertainment, but not sites that offer user-generated content or educational programs. "In its current form, Binge On turns the mobile Internet delivered by T-Mobile into a space for watching commercial entertainment," she writes. "And it hurts T-Mobile's subscribers as listeners, making it harder for them to benefit from the breadth and depth of video content on the Internet."

When the Federal Communications Commission passed net neutrality rules last year, the agency didn't explicitly prohibit zero-ratings programs. Instead, the rules only flatly prohibit broadband providers from blocking or degrading service and from creating online fast lanes. But the regulations also contain a broad "general conduct" clause that prohibits ISPs from interfering with people's ability to access Web content. Zero-rating could potentially violate that prohibition depending on the circumstances; the FCC has said it intends to take a case-by-case approach the question.

The agency recently questioned T-Mobile about Binge On, but hasn't publicly criticized the service.

For its part, T-Mobile says its customers with data caps are now streaming more than twice as much video than before Binge On. T-Mobile on Thursday also made the service easier to control by rolling out new short codes that let people (#BOF# to turn off Binge On and #BON# to activate it) opt in or out directly from their smartphones.