One of the biggest concerns that Twitter’s board of directors had with naming Jack Dorsey as the company’s permanent CEO was the fact that he was already the CEO of Square, but obviously they decided to go through with the decision anyway. This means Jack Dorsey is now among the handful of people in the world that are CEOs of two major companies, the most famous of which is Elon Musk, who runs both SpaceX and Tesla Motors at the same time. However, in a recent interview, Musk warned Dorsey that running two companies at once is a bad idea, and recommended that he not do it.
