Check the account history of the source. Two red flags are the number of posts and how long the account has been active. If it claims to be a well know source(like CNN or CBS) and only has a few posts in its history that are a clue. If it's a well know source and the account have only been active a short time that is another red flag.
Images of an event are often reused to deceive people. You can check if an image has been used before on a reverse image search service like TinEye.
Fake news stories abound on Facebook. Most of the postings are produced by scammers looking to make money on the number o
f clicks these stories receive.
Mark Zuckerberg, the founder, and CEO of Facebook says they are working on a way to weed out these stories. In the meantime, some creative people have come up with solutions of their own.
The Washington Post ran a story at this link on November 11, 2016, about a group of college students who developed an algorithm that authenticates what is real and what is fake on Facebook.
A programmer named Daniel Sieradski has developed a Chrome extension called the B.S.Detector. Read about this hoax detector at this link.
