Mark's got 250 billion dollars, founded a 2 trillion dollar company, and is quite possibly the wealthiest self-made person alive today. It is highly likely Mark also possesses some form of security clearance from the NSA related to issues adjacent to his company. It it also likely that Mark has some form of kompromat
Donald Trump is a pedophile and a lying grandstander who has always talked tough and backed down when up against someone who knows what they are doing.
Donald Trump could try to put Mark in jail. Mark has hundreds of billions of dollars to prevent the government from touching him. It wouldn't happen. The second Donald Trump tried shit, Mark would simply buy the top 100 law firms in the nation, and have them work together to stop Trump, and Trump would back down.