Online streaming giant Netflix admitted to sending lower quality video to mobile subscribers on AT&T and Verizon networks to help them avoid surpassing data caps.

The company has said that increased usage of the site on mobile devices has led to many customers worrying about surpassing data caps. The company admitted it has been sending lower resolution feeds to members on mobile networks with data caps for over five years.

“We believe restrictive data caps are bad for consumers and the Internet in general, creating a dilemma for those who increasingly rely on their mobile devices for entertainment, work and more,” said Anne Marie Squeo, a member of the Netflix corporate communications team on the Netflix Blog. “It’s about striking a balance that ensures a good streaming experience while avoiding unplanned fines from mobile providers.”

Netflix was forced to reveal this information after T-Mobile CEO John Legere posted a video on Twitter claiming AT&T and Verizon customers receive lower quality video from Netflix than T-Mobile users do.

T-Mobile’s Binge On program allows users to stream unlimited content from services such as Netflix, YouTube, and and Hulu without it counting against their monthly data allotment.

AT&T and Verizon responded that they have never adjusted video quality. “We’re outraged to learn that Netflix is apparently throttling video for their AT&T customers without their knowledge or consent,” said Jim Cicconi, AT&T Senior Executive Vice President of External & Legislative Affairs, in a statement.

Randolph May, president of free market think tank the Free State Foundation, argued that throttling leads to double standards. “Netflix’s complete lack of transparency about the practice, especially in light of its strident advocacy against treating Internet communications differentally is pretty stunning,” he said.

The issue of throttling is also contentious as it is prohibited under the Federal Communications Commission’s Open Internet provisions, which prevent Internet service providers from blocking or slowing transmission speeds of content.

Netflix has revealed that it is developing a “data server feature” which will allow users to set their own desired video quality in order to manage their data usage. The feature will let subscribers “stream more video under a smaller data plan, or increase their video quality if they have a higher data plan,” the company added.

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