I'm trying to think of other ways to monetize this without ending in prison, and not really coming up with much...
Sure, you could short stocks and then make "Aaah, Tesla is going bankrupt!" tweets... But without an army of lawyers and accountants and money to pay them, it's hard to anonymously short stocks.
You could bribe people with publishing DM's - but again that's pretty high risk. And how do we know that hasn't already happened?
Maybe shorting wouldn't have been needed. Just buy from the dip and trust that the stock recovers when twitter confirms hacking. But requires a lot of cash that the attacker probably doesn't have.