Just a narrative being peddled [0]. The mainstream media lost their grip on "the people" so now need to brand anything that isn't themselves as "fake news". Google Trends shows how blatantly obvious the narrative crafting is. It's only suddenly an issue because the MSM needs it to be. So within a very short amount of time you see MSM like the NYT or WaPo posting articles about 'Fake News' and getting everyone to start talking about it.

[0] http://i.imgur.com/lWjnRqt.png

Fake news started spiking in Google Trends around the election because that is when fake news became profitable.

We are talking about blatant spam sites in which the owners openly admitted to making up stories out of whole cloth.

Sure. Exactly. I just added a /s to my post.. ;)

The number of people online, the level of engagement, and the money being made in online advertising, is unprecedented. I don't know what impact it had on the election, but it was definitely something that has attracted more attention due to the campaigns. It's not unusual for a problem that has existed for a relatively long-time to suddenly come to the attention of the legislature when it rises in prominence.

Fake news became profitable right around the time when a major candidate ran on a platform that peddled conspiracy theories. What a surprise!

Fakenews/webspam has been profitable for years. I've seen articles with titles like "Martin Sheen dead!" for a lot longer than the 2016 US Presidential campaign (which, granted, seemed like it lasted forever)