Fake news is as old as time and dates back to well before the Internet.
Just to give an example: contrary to what always has been said, it wasn’t Nero that set fire to Rome (on the other hand, the Roman emperor made up other fake news to defend himself, accusing Christians of the misdemeanour).
Compared to ancient times, however, today there is a huge difference: the web works as an enormous sound box for all kinds of news and also offers a lot of information, putting experts and non-experts at the same level, empowering small groups that can become very aggressive. The remedy? This is also as old as time: teach yourself to be logical and practice being critical!