FCC Chairman Tom Wheeler once called T-Mobile's Binge On feature "highly innovative and highly competitive," but it looks like things have changed since then. The agency has summoned not only T-Mobile, but also AT&T and Comcast to answer questions about their data cap exemption offerings, according to Ars Technica. For T-Mo, that service is Binge On, which allows subscribers of qualifying data plans to stream videos from select services such as Netflix, Hulu and HBO for free. AT&T's Sponsored Data and Data Perks Program allows subscribers to stream content from sponsors without eating up their data allowance. Finally, Comcast has an add-on service for XFINITY internet subscribers called Stream TV, which is exempted from customers' monthly data usage.