This is merely the latest episode in a long story.
Judge Alexandre de Moraes was selected for the Brazilian Supreme Court(STF - Supremo Tribunal Federal) back in... 2016-7, when the President was Michel Temer; Temer did so in exchange for support from PSDB(Brazilian Social Democrat Party) - Moraes had occupied many positions in the Judicial Branch of São Paulo State, a State which had been governed by successive PSDB administrations since the late 1990s. Moraes was put into the STF to be PSDB's man there.
Enter Jair Bolsonaro's presidential bid in 2018. This was a major threat to PSDB; the party had become one of the most powerful parties of Brazil as it became the counterpoint to PT(Worker's Party), being the rival of PT in presidential elections, as well as being the party acknowledged as the head of the opposition since PT won the presidential election of 2002. The fact that PSDB was merely a centre-left party compared with the PT's left made Brazilian elections merely a choice between centre-left and left(what is sometimes called "Teatro das Tesouras", the Scissors' Theatre). Bolsonaro was the first viable presidential candidate of the 'right' since(arguably) Fernando Collor de Mello in 1989, and in the 2018 election, the PSDB's candidate earned less than 5% of the vote in the first ballot.
Therefore, PSDB became Bolsonaro's biggest enemy, even though the leftist coalition was the most outspoken one, being fully behind every obstructionist measure by the leaders of the House of Representatives and the Senate during the first year of Bolsonaro's administration(2019), as well as the STF's veto on some of Bolsonaro's appointments(biggest one was the appointment of the chief of the Federal Police), something they didn't have the prerrogative to do. When COVID came in the following year, while the propaganda was on that every single decision of Bolsonaro to fight the pandemic was the wrong one, the STF started usurping the Federal Executive Branch's powers to either give them to the State Governors or simply saying he wasn't allowed to do it. Moraes was an important part in those efforts(although not the main one). After 2021, Moraes became ever more important in hobbling Bolsonaro, coming to the point that during the 2022 election, Moraes basically was vetoing whichever Bolsonaro campaign decisions or ads he wished(and of course, he vetoed the most effective ones, while not touching the Lula Campaign ones).
Now we come to social media. Bolsonaro's success in 2018 is widely attributed to his camapign's social media efforts(something I don't think it's the whole truth - the support of Pentecostal Evangelists was as critical, if not more so). In 2019, some Representatives who had initially supported Bolsonaro, but soon broke up(mostly unsatisfied with the division of spoils), started raising some noise about Bolsonaro's success being due to 'fake news' on social media, which gave the STF the excuse to start an investigation led by... you guessed it, Alexandre de Moraes. Since then, that highly irregular investigation(where Moraes acts as prosecutor, judge, and sometimes as jury), has been used to hammer Bolsonaro's supporters(as well as those who personally displeased Moraes). Ordering social media companies to ban accounts of those the investigation deemed offenders, or to give personal information about them to be used in further investigations became commonplace, with social media companies being threatened with daily fines and/or banishment in Brazil for noncompliance(which is why you can't access Rumble or Locals without a VPN in Brazil). This has only grown more frequent since the January 8th, 2023 idiocy - now 'fake news' is deemed 'an attack on democracy'.
It looks like Elon Musk has grown tired of this shit and decided he won't play this game anymore, and if it means Twitter leaves Brazil, so be it. So far, the only response on Moraes part has been to include Musk as someone to be investigated in the 'Fake News' Inquiry last night - Musk made a Brazilian public servant work on a Sunday, perhaps his greatest accomplishment ever. So far, it seems that, in the short term, Twitter will be banned in Brazil.
However, there will be backlash - even though it's not WhatsApp(most used social media in Brazil - it's ubiquitous here), enough people use, make money of and hunt for political engaement in Twitter to piss off a lot of people(Telegram isn't nearly on that level, although it may become so, especially if Twitter gets banned and everyone moves to it). And Moraes is vulnerable to pressure on this - he's hated throughout Brazil(as is the entire STF), and those who vocally support him on Twitter(the irony) are mainly doing so because he's going after people they don't like. Some of them are even clever enough to understand he could do this to them as well if he were allowed to. My guess is Moraes is setting himself up to become a scapegoat. It may not happen now, but I do think this is the beginning of the end for him.