Elon have an army of followers with size of multiple 4chan's and some of them are obviously less stable than others. He is aware of this fact and over years he did not act responsible about it.

Also he is protected by an army of lawyers so he can smoke some weed and tweet that he thinks that you @memish is a pedophile or Hunter Biden friend or MAGA supporter or whatever. And you'll get tons of death treats as result.