Elon musk must have purchased a staking power of 9%, in order to express opinions freely, without being restricted by the co-founders of Twitter, because he's part of the owners now. Remember, he was accused of using Twitter to promote dogecoin, which many deemed monopoly too, due to the influenced he constituted, made lots of people investing in the digital coin, resulting in huge money loss, as the coin dropped down drastically low within short term interval.
As for the laws of United States of America, I don't know about, but if Elon musk violated a rule, he should be penalized for it no doubt. Their should be equality when it comes to law enforcement between the rich and the poor.