Brazil’s approach is notable for how it seeks to force companies that provide the backbone of the internet to block Telegram’s web traffic. The policy even covers people who try to use software to get around the ban by routing their web traffic through other countries. Mr. de Moraes said anyone caught doing so would face a $20,000 fine.
The policy “is trying to attack from several fronts, so maybe it will be feasible,” said Lucas Lago, a Brazilian software researcher.
While misinformation is a tremendous concern on the platform, many major news outlets use Telegram to deliver content, including The New York Times.
Supporters of Mr. Bolsonaro immediately criticized the ban. Carla Zambelli, a Brazilian congresswoman and a longtime supporter of the president, said on Twitter that Telegram was “the only current tool in which we have freedom of expression” and called Mr. de Moraes a “tyrant.”
Senator Humberto Costa, a left-wing critic of Mr. Bolsonaro, said that “the Fake News Stock Market has plummeted. The Bolsonaros lost part of their heritage of lies.”
Representatives for Mr. Bolsonaro and Mr. de Moraes did not respond to requests for comment. Apple and Google declined to comment.
Ms. Oates, the University of Maryland professor, said that Telegram had become well-known for ignoring government orders and requests for data. Yet she added that because Telegram was so overwhelmingly popular with the right wing in Brazil, the order could be perceived as a partisan move.
“On the one hand, it’s understandable to want to regulate your media space, and platforms like this exacerbate existing problems,” she said. “On the other hand, it can be perceived as unfair because this targets a particular group of people.”
André Spigariol contributed reporting from Brasília, Brazil, and Leonardo Coelho from Rio de Janeiro.