Elon Musk has urged leading AI laboratories and Chinese companies to cross-test their systems. He made the appeal while some in tech are asking for a slowdown in AI work. Musk himself has major AI investments. Tesla shares slid following the speech. Musk also appeared at the head of Forbes' annual ranking of the wealthiest Americans. He brought up once more the idea of combining Tesla and SpaceX. Separately, reports say sexually abusive imagery of children remains on X, even though Musk committed to fixing it.