Susan Walsh/AP; Erin Scott/Reuters There's no love lost between Elon Musk and Mark Zuckerberg. The billionaire tech CEOs — who helm Tesla and SpaceX, and Facebook, respectively — have been feuding since at least 2016, when a SpaceX rocket explosion destroyed a Facebook satellite. Since then, they've butted heads over everything from artificial intelligence to Facebook's data-collection practices. Most recently, Musk tied Facebook to the violent insurrection in Washington, DC, describing it as a "domino effect." Visit Business Insider's homepage for more stories.