I actually know how these things work and you don’t need to lecture me with what you thought you understood someone bragging in a PowerPoint to mean.
They get that info through legal processes like subpoenas that Twitter is entitled to fight because they’re private. And they put lots of legally unnecessary effort and their own money into fighting them; other platforms don’t try nearly as hard to stop it. See the DevinCow case.
Of course Elon just fired the exec who did this.