Who gets to decide what qualifies as "fake news" vs "real news"? Thus far the bulk of the stories surrounding the subject are largely just the left-leaning mainstream media outlets being butthurt over Trump's win and Bannon giving Breitbart a huge heaping of credibility. This move by the left to censor various news outlets is largely just a response to them getting their comeuppance for their hubris.
In the end let's call this #fakenews trend what it is: an attack on conservative and right-leaning media outlets not already in the fold of what constitutes the "mainstream media". Even if you don't take a news/media company seriously, that doesn't for a second think they should be excluded from the marketplace of ideas. That includes those on the fringe like Infowars, Hell, even The Inquirer has broken some very real and legitimately big stories over the years.