Zuckerberg reacts to Twitter for fact-checking Trump says social media must not be the “arbiter of truth”.

Twitter CEO Jack Dorsey has defended the platform’s decision to fact-check Donald Trump’s tweets after Facebook chief Mark Zuckerberg questioned the move.

Earlier this week, Twitter added fact-checking labels to two tweets from the US president which made unsubstantiated claims about “fraudulent” postal voting in the US.

Trump threatened to “close down” social media sites in response, claiming they are biased against him and other conservative voices.

Zuckerberg has now also weighed into the argument, telling Fox News that Facebook had a different approach and that private companies such as social media sites should not be the “arbiter of truth”.