Image copyright
Reuters
Jack Dorsey said details would follow in November
Twitter is to ban all political advertising worldwide, saying that the reach of such messages “should be earned, not bought”.
“While internet advertising is incredibly powerful and very effective for commercial advertisers, that power brings significant risks to politics,” company CEO Jack Dorsey tweeted.
Social media rival Facebook recently ruled out a ban on political ads.
Social media firms are under particular scrutiny ahead of US elections in 2020.
The ban will be enforced from 22 November, with full details released by 15 November.
Mr Dorsey explained his position in a thread of tweets.
How does Dorsey justify the ban?
Internet political ads, he said, presented “entirely new challenges to civic discourse”.
These challenges included “machine learning-based optimization of messaging”, “micro-targeting, unchecked misleading information, and deep fakes”.
“It’s not credible,” he wrote, “for us to say: ‘We’re working hard to stop people from gaming our systems to spread misleading info, buuut if someone pays us to target and force people to see their political ad…well…they can say whatever they want!'”
Countering the argument that the new policy might be seen as favouring leaders already in office, he pointed out that “many social movements reach massive scale without any political advertising”.
Ads in support of voter registration would not be affected by the ban, he added.
What is Facebook’s policy?
Facebook founder Mark Zuckerberg went before an audience of students in Washington DC to defend the firm’s decision not to ban political adverts that contain falsehoods.
He had considered barring all political ads on his platforms but said he believed the move would favour incumbent politicians and whoever the media chose to cover.
The company should “err on the side of greater expression”, he argued.
Image copyright
Facebook
Mr Zuckerberg gave his speech to an audience of students and others at Georgetown University in Washington DC
A spokesman for Democratic presidential hopeful Joe Biden had criticised the firm for refusing to remove a video posted by President Donald Trump’s 2020 re-election campaign which promoted an unproven conspiracy theory involving the former vice-president and his son.
“It is unacceptable for any social media company to knowingly allow deliberately misleading material to corrupt its platform,” Mr Biden’s press secretary said.
Fellow Democratic candidate Senator Elizabeth Warren then paid to run an intentionally misleading advert on Facebook that claimed Mr Zuckerberg had personally endorsed Donald Trump for re-election.
She said she had done so in protest against the firm’s decision to allow politicians to run ads containing” known lies”.