AT&T’s HBO and Cinemax premium channels have been blacked out to Dish Network and Sling TV subscribers in a dispute over an carriage agreement Dish said it is the first time HBO has ever blacked out a distributor. Dish said that HBO made “untenable demands” designed specifically to harm customers, particularly those in rural areas, as well as damage competing pay-TV providers. AT&T, which acquired HBO’s parent company Time Warner earlier this year, also owns DirecTV and DirecTV Now.