It's not mass censorship. It's editorialization. Something we've lost an appreciation for in our fetishization of a dystopian future that's always just over the horizon.
Facebook tried doing this to combat actual fake news (the one that ironically comes from the political segment in the U.S. most likely to cry wolf about it). This process was then characterized as facebook policing political content in a biased manner -- despite the fact that blatantly false content happened to continually come from sources with a conservative bent more often than not, which isn't Facebook's problem to deal with.
Point being, it's not censorship. And I wish any attempt to fight false information wasn't disingenuously painted as these organizations having some kind of political agenda or as "censorship". We need content aggregators of every kind (facebook, google, reddit, and even HN) to be more editorial, especially and specifically when content is presented in a manner that might help how credible that content looks. This whole wish-washy "oh just let the people decide what they wanna see, it'll work out in the end" with a nice touch of "all opinions matter" clearly hasn't and isn't working.