Local news stations fall into two categories: “owned and operated stations” whose content is controlled by a network or larger parent company, and “affiliate” stations that are not owned by a central network, and thus do not have to use the network’s content. So a local “Fox” station might be entirely independent, or it might be controlled by Rupert Murdoch’s 21st Century Fox — and they do not have to tell viewers which they’re watching.
By owning these local stations, Murdoch and 21st Century Fox can push narratives of their choosing onto large local audiences, often running the same news packages and hosting the same personalities that appear on the Fox News cable channel. According to federal communications law, a single company can own any number local stations so long as they collectively reach “no more than 39 percent of all U.S. TV households.”
21st Century Fox recently expanded into the San Francisco market, broadening their reach to 37 percent of U.S. television homes. They now own 28 stations in 17 markets.