News Corp is a conglomerate owned by Rupert Murdoch. News Corp owns:
News Uk
New York Post
Financial News Services
Harper Collins (Book Publisher)
Wireless media ( Radio inc, Talksport and Virgin Radio).
Rupert Murdoch is a media mogul who used to own New Corporation which he later split into News Corp and 21st Century Fox. People are scared of Murdoch because they believe he has too much power and influence over the public.
Media Plurality is having multiple media services, it's the idea that there should be loads of places to go and obtain the news but by having Oligopolies it limits media plurality. without this people will be limited to the type of media they consume which may be biased or unfactual.
Power without Responsibility is a book written by James Curran and Jean Seaton, where they argue that the press hold a lot of power but have little responsibility. The concentration of ownerships make this worse.