Donald Trump has signed an executive order on Thursday targeting social media companies following his threats to “strongly regulate” or “close down” platforms after Twitter fact-checked a pair of his tweets making false statements about the extent of voter fraud in the US.The president was incandescent with fury on Wednesday after Twitter moved to cast doubt on his spurious claims by directing readers to a topic page where they could “get the facts” on the issue, wildly accusing the company of “stifling FREE SPEECH” in a tweet whose very existence undermined his argument, despite social media platforms making similar efforts to combat campaign misinformation ahead of US elections.