Because you are selling something that allows a third party to receive a service for free from some company. IOW, your “service” is to sell something that allows someone to “steal” their service. They go nuts over that sort of thing, and they’ll tend to go after the entity selling, rather than using, the info or device.
If they’d just been playing with their own equipment and kept their mouth shut, I doubt DirecTV would have acted even if they knew about it - too much time/energy/trouble. Once you start selling that info or device to everybody it will get out of hand and they have to pursue it, IMO.
That's my suspicion - that they were selling something. Otherwise I don't think anyone would care that 17 people were getting free TV. And I don't think they could pursue any theft of service type deal for 14 million with just 17 people involved. I could be wrong.