For one example, YOU can open an LLC to hide your identity if you are investing in Real Estate, and it quite ok and legal. You can also use an LLC to pass money through without your name being attached, but Im not quite sure of the details as to when it is legal or illegal, though its common knowledge that these shell companies are sometimes used to launder money.
I havnt been keeping up with how many shell companies Hunter supposedly owns, but..... if he had 20 of them and is bringing in money internationally, then its worth investigating. I could see a scenario where if a person is bringing in millions of dollars, you would'nt want all that money flowing through one company because it would draw attention. You might spread it out over 20 different LLCs