In November, T-Mobile launched Binge On, letting customers stream videos at a reduced quality from services such as Netflix, Hulu and HBO without incurring any data charges. However, YouTube — which isn't participating in the program — has claimed that the carrier was throttling its traffic as well. T-Mobile has responded to the comments, stating that it wasn't throttling, but "optimizing" YouTube data.
In a statement to DSL Reports, T-Mobile stated:
Using the term "throttle" is misleading. We aren't slowing down YouTube or any other site. In fact, because video is optimized for mobile devices, streaming from these sites should be just as fast, if not faster than before. A better phrase is "mobile optimized" or a less flattering "downgraded" is also accurate.
It looks like T-Mobile is optimizing all video on its network, irrespective of whether the service has partnered with Binge On or not. There's no excuse for throttling videos without user content, especially as Binge On is enabled by default. You can however switch off the service altogether by heading to My T-Mobile > Profile > Multimedia settings.