Whitelist or blacklist or assigning PageRank to websites are tempting but also controversial because it will fall under the accusation of censorship. Take the below link as an example:

http://www.breitbart.com/2016-presidential-race/2016/10/16/m...

This is not 'fake' news, in a literal sense, because it just says someone is about to release something about Clinton. But for some people, this news could simply be seen as an indictment. Can we claim it is fake in that sense? As I have said above, it is equally controversial to penalize such websites for editorialization, because find story out of non-story is how most news agencies makes money and they have incentive to do this. Blame modern media and journalism for this.

In the end, using one simple algorithm to battle this is kinda of naive, not because it won't work for simple cases, but it fails to cover corner cases. In such scenario, human judgement is still crucial.