If you go to "Help" on Facebook and "Basics" and "News Feed Basics" you will find the following piece of information in their FAQ;
"How does News Feed determine which content is most interesting?
The News Feed algorithm bases this on a few factors: how many friends are commenting on a certain piece of content, who posted the content, and what type of content it is..."
The key word here is "determined"; a euphemism for "Decided."
In other words, a computer somewhere in Facebookland, controlled by Mark Zuckerberg, is deciding what appears in your news feed.
If the government decided that only phone calls, letters, newspaper reports, TV programmes, songs and radio news reports which were vetted by a computer algorithm it controlled could be seen by you, it would be described as Orwellian, and it would be; by the time it happened we would have already been taken over by a totalitarian state.
So how come no-one minds when a private company does this? State censorship is state censorship, private censorship is "just business..."
In fact on other websites people are used to being able to control what they see and how it functions, being able to control all sorts of settings. This control has largely been removed by Facebook, it is now a much more centralised, top-down, regimented outfit than it was in the past. Doubtless this controlling centralisation will be refined further until you only see posts which mention certain brands or which contain no political (or politically left-wing) content. This is something which will start to become frustrating for Facebook users, especially now those randon, throw-away one-liner conversations which made social networking a pleasure now seem to have become a thing of the past.
I'm starting to migrate onto Google+ for the moment, which at least isn't trying to impose its own thought control on me, I suspect someone with a bit of technical skill and an element of opportunist entrepreneurship will find the niche in the market for a social networking site that lets users control what they see, when how and in what order...
Zuckerberg has ended up destroying the goose that layed the golden egg; he will end up with a meaningless, over commercialised sanitised social network which bores more and more people until only the mindless use it, the rest of us will have gone elsewhere...