Mark Twain famously said in 1921 that "a lie can travel around the world and back again while the truth is lacing up its boots".
Nearly 100 years later nothing has changed. In fact, frictionless sharing of content or "up-voting" of content via algorithms merely by liking it on social media has made it more easy than ever for a lie to fly around the world whilst the truth is still struggling with its shoes.
The real challenge of "fake news" is that people will continue to like and share it, even once it's been debunked. People share content in part because it's a signifier - it says something, publicly, about the sharer, their views, their political allegiances, themselves. And they don't pay much attention to the veracity of the source material.
The other challenge, of course, in the internet age is when there is 2.5 exabytes of data produced every day, how can you possibly verify everything you read? It's a challenge. But if you were so minded, you'd see that Mark Twain never actually said the quote I started this post with, it's just been attributed to him over the years on the internet.
“With Facebook trying to throttle it and say, ‘Don’t share it,’ it actually had the opposite effect.”