Prakash Singh / AFP / Getty Images Twitter CEO and cofounder Jack Dorsey

Twitter is planning to ban political ads from its service globally, the company announced Wednesday via a series of tweets from its CEO Jack Dorsey. The ban will go into effect Nov. 22. Dorsey said the ban will cover ads about specific candidates and issues — the broadest possible ban. Some ads will be allowed to remain, including those encouraging people to vote. According to a Twitter spokesperson, news organizations are currently exempt from its rules on political advertising, and the company will release full details on exemptions next month.

We’ve made the decision to stop all political advertising on Twitter globally. We believe political message reach should be earned, not bought. Why? A few reasons…🧵

This is a major shift in policy for Twitter. Ahead of the 2016 election, the company sold new targeting options to campaigns and promoted hashtags ahead of the debates. But during the campaign, Twitter was beset by a misinformation campaign coordinated by a Kremlin-linked troll farm and even tried to sell Russia Today 15% of its US elections ad inventory. The company does not want a repeat this year.

Twitter’s move comes as Facebook has faced heavy criticism for political ads, which permits candidates to lie according to a policy the company clarified earlier this month. CEO Mark Zuckerberg and his executives have defended this move by saying that they do not want the company to be arbiter of truth, and instead will allow the public and media to assess the truth of claims. “While I worry about an erosion of truth, I don’t think most people want to live in a world where you can only post things that tech companies judge to be 100% true,” Zuckerberg said in a speech earlier this month at Georgetown University. The policy has sparked a backlash from presidential candidates including Elizabeth Warren — who ran a false Facebook ad to underscore what she saw as the policy’s absurdity — and some of the social network’s own employees, who have circulated a letter decrying the decision and suggested their own changes. In his Twitter thread, Dorsey took a swipe at Facebook's policy, noting that it is not credible 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!”

For instance, it‘s not credible 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! 😉”