Facebook says it is taking steps to weed out phony news articles after widespread criticism that fake or misleading news on the platform helped swing the US election to Donald Trump.
Ideas include posting warning labels on false content and programming smarter algorithms to detect fake news. Like Google, it has banned fake news sites from making money through its advertising network.
But what is fake news, and can it be stopped? Chief executive officer Mark Zuckerberg said it was a complex philosophical problem.
How do we distinguish between fake and satirical news, or deliberate falsification and mere bias?
The truth is out there.Take the quiz to see if you can spot fake news