CNET

John Legere may be one of tech's most colorful and uncensored CEOs. But he apparently knows when he's crossed a line.

T-Mobile's CEO on Monday apologized for offensive comments he made last week about the Electronic Frontier Foundation amid a debate over his company's Binge On unlimited streaming service. But Legere didn't relent in his defense of Binge On as being in line with principles of a free and open Internet.

Legere and his company faced some heated criticism last week for Binge On, which lets customers stream an unlimited amount of video from certain services to their smartphones without busting their monthly data caps.

While Legere says customers are benefitting from the program, EFF, an Internet rights group, accused T-Mobile of throttling, or slowing down, all video traffic to a data rate of 1.5 megabits per second, even for customers not subscribed to Binge On and even when the network was not congested with other traffic. The EFF claims that video streamed at this low bit rate can result in a poor user experience, including buffering. This follows similar accusations from Google's streaming video service, YouTube, which has declined to participate in Binge On.

Amid a Twitter debate Friday, the EFF asked Legere if T-Mobile is altering the video streams or just limiting their bandwidth. Legere responded in a video.

"What Binge On does, it includes a proprietary technology and what the technology does is not only detect the video stream but select the appropriate bit rate to optimize to the video, the mobile device," he said. "That's part A of my answer. Part B of my answer is, who the f--- are you, anyway, EFF? Why are you stirring up so much trouble, and who pays you?"

Those comments further stirred the pot, to the point where at least one small video company reportedly decided to halt participation in Binge On.

In Monday's open letter to consumers, however, Legere backtracked... sort of.

"Look, by now you know that I am a vocal, animated and sometimes foul mouthed CEO. I don't filter myself and you know that no one at T-Mobile filters me either (no, they don't even try). That means I will sometimes incite a bit of a 'social media riot,' but I'm not going to apologize for that," he wrote. "I will however apologize for offending EFF and its supporters. Just because we don't completely agree on all aspects of Binge On doesn't mean I don't see how they fight for consumers."

He went on to say that he and the EFF have a common mission to protect consumers' rights and to give consumers value and looks forward to sitting down with EFF to that end. "Unfortunately, my color commentary from last week is now drowning out the real value of Binge On -- so hopefully this letter will help make that clear again."

That said, the apology came only after reiterating that T-Mobile remains steadfast in it's position that Binge On "absolutely supports" the Federal Communication Commission's Net neutrality principles, which require all services on the Internet be treated the same.

The FCC has said it plans to look into Binge On, just one example of a practice known as "zero rating," which allows Internet service providers to not count data usage for certain applications against a customer's monthly cap. Critics have maintained zero rating services put smaller competitors at a disadvantage and show that data caps are unnecessary.