They have essentially lost all ad income driven by Brazilian users. I'd say that's quite a bit of leverage. Furthermore, SpaceX have had local assets frozen. That seems like some leverage to me. Starlink have now decided to comply with X blockage in the country [0] after Musk rattling his sabre saying they wouldn't. It _feels_ like there is at least some leverage.
> They have essentially lost all ad income driven by Brazilian users
This one, at least, isn't really leverage. If they did comply the ad revenue would be lost anyway. If Twitter does somehow win a legal challenge they can at least try to sue for lost ad revenue, they likely couldn't make that case if they chose to comply.
I'm not sure how they can legally go after SpaceX here. Definitely not claiming to know Brazilian law here, it just seems surprising that they could be roped in only for having the same founder/CEO. Unless I'm mistaken they aren't even sibling companies under a shared corporate parent.
> If they did comply the ad revenue would be lost anyway.
If they had complied, only a subset of Twitter accounts would have been removed from the website. All over 100 million Brazilian users would still be generating traffic to them and the ad revenue that comes with it. I think this is pretty large leverage.
> I'm not sure how they can legally go after SpaceX here.
> it just seems surprising that they could be roped in only for having the same founder/CEO.
From my understanding (which is developing along with the whole situation), even big names in Brazilian law are disputing this. So far I haven't seen anyone say the decision was illegal, but I have seen some questions being raised.
That said, my (very poor) understanding is that it's not because Musk is founder or CEO, but because he is the largest investor in both, exerts significant control over both, and essentially uses both in tandem in order to pursue his interests. Again in my very poor understanding, these factors combined made the judge rule the 2 companies more or less like one large financial group, giving him the ability to freeze one company's assets as insurance for the other's unpaid fines.
Pardon my lack of legalese or proper understanding and description of things. Hopefully this helps a bit on your own journey of understanding.
[0] https://news.ycombinator.com/item?id=41439798