https://www.youtube.com/watch?v=Nt8d2k9QyC4&t=585s
Right at the 11 minute mark this tactic was mentioned having a company registered in the small caymen islands as well.
And that is why it is recommend having your crypto holdings with a company based and registered in the U.S so if need be they can be sued if they pull an exit scam or try and hide behind loop holes of the law when it comes to doing dealings overseas such as bitmex's entire outfit being licensed there.
Exactly what you said: "They can not be touched!"
Pavel Pogodin is the lawyer going ahead with this law suit. So you will just have to check on his track record to see what their success rate is before saying this wont go very far.
https://decrypt.co/29274/new-class-action-accuses-crypto-exchange-bitmex-of-racketeering-fraud