You forgot:
Gannett who owns close to 100 newspapers, 22 tv stations, careerbuilder.com, the USAToday weekend magazine that appears in almost every city's newspaper, and of course USAToday newspaper.
Clear Channel that owns who knows how many radio and tv stations, premier radio network, the vast majority of outdoor advertising.... and they have been preparing to go private and that would mean they would not have investors to answer to.
(This website will show you how much outdoor advert they own.... you maybe shocked:
http://www.clearchanneloutdoor.com/ ) They talk about how they put the ads in malls, on taxis, buses, on mall escalators, etc. etc.
Viacom is second in outdoor advertising.
Then there's Hearst, Cox, Comcast, Cablevision, SBC.... theis website covers it all pretty much:
http://www.cjr.org/resources/index.php?c=clearchannel
If we went into the companies boards and stockholders, I have a feeling we'd find the same people owning major chunks of each of them (in the guise of "institutional holders", "mutual fund holders" etc.) Big players are Barclays, Chase, Vanguard.
The argument can be made that the "institutional" and Mutual Fund" holders act as protection and they don't own that much and so on. Quite possibly, but I wonder how much stock in Chase, Barclays, Vanguard and so on, the Murdoch's, Redstone's, GE's, etc own.
The point with owning all the major media isn't controlling it right now... its being able to set the prices and who gets advertising time. They can determine the elections all the way down to locally by controlling the prices of the advertising. Those that may have a truly great message but can't get the funding to get off the ground are doomed before they start.
Once the internet is consolidated, then they can control what people see and hear almost totally.... but you can never control it totally and there will always be a rogue or 2 out there that will gum things up.