This was inevitably going to happen someday due to net neutrality rules, the FCC has thrown a number of questions at AT&T over their offer that allows customers to use their DIRECTV service without it counting towards their data allowance. AT&T is not alone, though, with Verizon also being questioned over their Go90 service which offers the same zero-rated deal.
The reason both companies have been questioned is simple, the FCC launched an investigation into the offers and has come to the conclusion that both companies are violating net neutrality rules by favoring their own services over competing ones. Both companies argue that the data isn't given out for free, with the video service providers paying for the cost of consumer data, instead of the consumers themselves, but the FCC believes that both carriers are at an advantage since they are the owners of both the network and video services, meaning the data that consumers use is essentially free. The FCC also stated that this harms consumers because they may feel forced to use their carrier's own video service, essentially giving them a significant advantage over rivals.
Now, looking at AT&T's DIRECTV service, consumers have to pay a monthly fee of $35 to gain access to the service, a price that is incredibly competitive considering the fact that it would cost the likes of Netflix or Hulu up to $47 a month per customer to offer just 30 minutes of free data every day on AT&T's network, without considering the charge of the service itself, a price the FCC considers too expensive for them to compete. AT&T believes their service only benefits consumers, though, and the company has been asked to provide additional information to the FCC before they make a final decision on December 15. The FCC will have to act fast, though, because Donald Trump takes over office on January 20th, and, historically, he has stated that he is not a fan of net neutrality rules. Regarding Verizon, the company has stated that they are still reviewing the inquiry, though they do believe that their service is non-discriminatory and obliges with current net-neutrality rules.
It remains to be seen what ends up coming from both of these investigations, but there is the possibility that, once Donald Trump becomes president, both investigations will be ignored and net neutrality rules could be significantly modified, therefore allowing both carriers to carry on as usual, but we'll see what happens.