Coincidentally I just read an article about the idea being implemented during a Hackathon at Princeton very recently [0]. Four students put together a very intelligent AI in 36 (!!) hours to verify articles posted on FB for truth, using the term AI lightly of course. They've also open sourced their project since then [1]. Obligatory chrome extension link [2].

[0] - http://www.sfgate.com/technology/businessinsider/article/It-...

[1] - https://github.com/anantdgoel/HackPrincetonF16

[2] - https://chrome.google.com/webstore/detail/fib/ofpheinlpjdffp...