As for combating this - there are no golden bullets. Even Google's search starts to lean towards sources that a given user visits more oft... or actually my search patterns fit to a given scheme that's abused by media outlets in their SEO.
I've had an idea for aggregating time-ordered news headlines for analysis to get a broad comparison of author and company leanings. This could be then shaped to a browser extension informing the user about that. The problem is that then it would be accused of labeling stuff with broad strokes.
(This mainly comes from me not remembering which news site likes which politicians and social issues.)
Arguably it doesn't even matter () because it's more profitable to run advertising along with donations/micropayments to diversify revenue streams. This also doesn't solve the issue of views as currency and the optimizations it drags along.
That, plus there's sure to be a young whipper-snapper on HN that will read the article and think, "what a neat idea that nobody has ever thought of..."
To be honest, this isn't even just about Facebook, I'm sure you could have the same argument about the majority of today's tech companies who are commoditizing information about users and using that to monetize.
Generally, though, this is a trend that is not slowing down, instead it's rapidly speeding up. In addition to that, the methods have become increasingly worse. I'd like to continue discourse on methods of combating this particular phenomenon.