Twitter CEO Jack Dorsey announced Wednesday that the mammoth social media company will halt all political advertising on the platform globally.

“We’ve made the decision to stop all political advertising on Twitter globally,” Dorsey wrote in the first of a string of tweets. “We believe political message reach should be earned, not bought.”

The chief executive went on to share some of the rationale for the company’s decision, saying internet advertising comes with “significant risks to politics,” including “unchecked misleading information” and “deep fakes.”

“A political message earns reach when people decide to follow an account or retweet,” he wrote. “Paying for reach removes that decision, forcing highly optimized and targeted political messages on people. We believe this decision should not be compromised by money.”

Dorsey also took a thinly-veiled shot at some of his competitors, namely YouTube and Facebook, over their political advertising policies. YouTube, a Google subsidiary, said last month that content created by political figures and leaders will be allowed to remain on the site even if it violates the company’s “community guidelines.” Around the same time, Facebook said it would not fact-check posts by politicians, and would allow such content to remain on the platform even if it breaks the company’s content rules.

“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!'” Dorsey wrote.

Facebook and Twitter came under fire for negligence during the last presidential-election cycle, when they allowed Russian actors, among others, to spread misinformation and attempt to sow discord on the site.